Completely regret eyebrow transplant. Want to pluck them all out. What are my chances of them never growing back?

They are different type of hair removal. First one, you have to choose a good eyebrow transplant surgeon and he can decids which hairs need to remove from your  eyebrows. (Wrong transplant hairs can be remove by laser or micro punchs)

As we see an increase in restorative eyebrow hair transplant procedure, we're seeing an increase in doctors performing the surgery who are inexperienced and unskilled. In order for eyebrow transplants to look natural and appropriate, the hairs must be placed in the right angle, shape, and density. This is easier said than done and unfortunately many doctors' skills fall short. Unfortunately for you, transplanted hairs are permanent. If you would like the hairs to be gone completely, you will need to utilize a permanent hair removal method such as laser hair therapy. Once the hairs have been removed, you can get another eyebrow transplant from an inexperienced surgeon who know's what he's doing. 

I am sorry to hear that you regret having surgery. The transplanted hair can be resilient and is often very strong, and will oftentimes persistently grow back. There are a variety of treatments each requiring multiple sessions to get satisfactory results. With each treatment the hair should come back thinner and thinner. Methods for removal include electrolysis, waxing and laser treatment.

Plucking wouldn't have any different effect than it would have on your normal hair. If you want those hairs to stop growing you need to visit your doctor who can recommend the best hair removal options for your particular case. Laser removal would probably be the best option but other choices are worth considering.

Yous should get a second opinion and get your eyebrows examined before a recommendation is given to you.  Without more information like pictures or an examination, it is difficult to give you are recommendation

I would seek the advice of another hair transplant surgeon and look in to doing a revision. It is possible to do laser hair removal of the area, but it might be a more logical approach to just have a revision treatment to get the best results that you can without wasting what you are able to still use. 

Eyebrow transplantation is a very precise procedure and should only be performed by an artistic full-time hair restoration surgeon with a a history of great results. If you pluck the follicles about 95% of the bulb will be removed and in 1-2 pluckings the hair will not regrow. If you have some native eyebrow hair you should leave it alone. See a full-time hair restoration surgeon for their advice. I will sometimes have patients remove bad result with laser hair removal be eyebrow repair. Many clinics in addition to ours offer remote consultations.