What should I do if my surgeon charged me for silicone implants but I received saline?

Since it has been 7 years, there is nothing that can be done. As soon as you were given your implants cards, you should have discussed the difference then with your surgeon. You have waited too long to do anything. If you want, you could contact the office, but I doubt anything can be done now.

I suggest you contact your plastic surgeon and discuss the matter with him or her.
If you’re uncertain of the terms or what type of implant was placed, then ask for copies of your medical record, including the consent form you signed, and the implant identification card you were given.
If your price quote or consent form is in conflict with what was delivered then there may be a breach of contract issue or possibly operating without consent issue.
Most likely there is simply a misunderstanding.
I suggest you try to resolve this in the easiest way possible.
Have you tried talking to your plastic surgeon?
Best,
Mats Hagstrom MD