I am sorry to hear of your difficult and challenging surgical course and recovery, and am glad your'e healed and able to ask about a better cosmetic result. Knowing what you do now, perhaps either you, or your surgeon, or both would consider doing one or more things differently.
Most surgeons I know, myself included, have a re-do or revisonary surgery policy that is discussed prior to any patient's initial surgery. Often it is printed on your quote sheet and/or consent form. Certainly you know you did not pay for two operations with your initial surgical fee quote "in case" you needed secondary surgery for any reason--the vast majority of patients would not be interested in paying for something they rarely would need, and nobody assumes THEY will be the one with the problem and re-operative need or request!
Thus, every patient gets the one-operation price, and there is (hopefully) a written policy about those times another surgery is necessary or desired, as in your case.
Then, there is the issue of "fault" that is the elephant in the revisionary surgery room when it comes to discussing who pays for what.
If your surgeon used poor judgement and damaged the blood supply to the abdominal skin that caused the fat necrosis that led to the seroma, that became infected, and that aggravated the puckered healing you now have, whose "fault" is that? Yours, for choosing a surgeon with less-than-perfect judgement, or the surgeon, for trying to give you the best result possible and over-doing by just enough to start the unfortunate chain of events?
Or, did you choose a non-ABPS-certified "cosmetic surgeon" with little or no training in plastic surgery (often because of a lower cost)? Or did you go out-of-country for that "cosmetic surgery" vacation experience and end up with a surgeon who was not even available for treatment of complications? Perhaps you were a smoker who did not stop, or "sneaked just one or two." or were exposed to second-hand smoke! If that was the case, it must have been your surgeon's fault for not telling you how truly serious this recommendation was, or you would have followed it!
Wow, that's an awful lot of potential finger-pointing going on! And trust me, it happens. So, assuming you did choose a reputable ABPS-certified plastic surgeon with excellent credentials and experience, and you followed ALL of your surgeon's recommendations to maximize your outcome and minimize your potential complications (activity restrictions, tobacco avoidance, garment/compression, cleanliness, etc.), and your surgeon did the best operation s/he was capable of--then your problems were really nobody's FAULT.
It certainly sounds as if your surgeon put in much more time and effort during your recovery (as did you, we certainly understand) than with the "usual" no-problem patient. Presumably, s/he did that without additional fee-for service, and you definitely had to spend $$ and time for doctor's visits, hyperbaric O2, bandages, and time off work or social activities. Truly, nobody sounds like a "winner" here.
And your doctor DID successfully get you healed so that you're around to be concerned about the cosmetic result both of you hoped for in the first place.
Bottom line here: both you and your surgeon have a stake in your final result. I would be almost certain your surgeon will re-operate to try to improve your result for no additional surgeon's fee. His/her time is worth significant $$, and that is what your surgeon contributes to your improved outcome in light of this spectacularly unfortunate and thankfully rare scenario. Your contribution to that improved outcome is your agreement to cover the surgical costs (operating room; anesthesia; supplies; and, of course, another recovery and all that entails). That is what most of us would do, and although that may seem unfair to someone who paid for surgery and had to go through what you did, it is ultimately the fairest, unless there are extenuating circumstances that we online consultants cannot be aware of (but that you and your surgeon ARE). Realize that this payment plan for revision surgery would be true even if your surgeon operates their own surgical facility. There are still costs, though they may be better controlled in this non-hospital setting.
One final comment while I'm on a roll: your surgical fees are paid for the performance of an operation (with all the skill, attentiveness, experience, and care your surgeon brings to bear on your behalf), NOT for a "promised" result or "guaranteed" outcome. Your surgeon did perform that procedure (and cared for you during the extended and difficult recovery), and you both were the unfortunate "victims" of a bad outcome. (There are worse ones, such as Kanye West's mom, so perhaps a bit of thankfulness is proper here, as I'm sure you know.)
If there was true negligence or malpractice that can be proven in a court of law, then that is a final avenue to travel down. But poor outcomes, complications, and even bad judgment is not malpractice, so the legal medical malpractice bar is pretty high.
If you communicate with your surgeon in a calm, reasonable, and non-accusatory manner, s/he will likely bend over backwards to make revisionary surgery as effective and cost-conscious as possible. But frankly, it is probably unreasonable to ask your surgeon to not only do "free" surgery and get you through another recovery, but also to pay for your OR, anesthesia, and other costs as well. (Small revision under local anesthesia--easy: no charge. But more surgery and full anesthesia is a different story.
Thanks for asking in such a non-blaming way, and please understand that I was simply using examples in my discussion above, and truly NOT pointing the "blame" finger towards you in any way. Individual patients may see certain aspects of my discussion in themselves, just as my surgical colleagues and I do in the surgical part. You see, if we've been doing this for a few years, we've all been there or in similar shoes once or twice! God bless, and best wishes!