I’ve been received treatment with Invisalign for about 2 years now, but the treatment isn’t going well. My case is too complicated for this treatment (I just found out) and my dentist did it anyway. I saw a few orthodontists and they recommended going with regular braces, so I want to do that.
However, how do I get my money back? how much can I get back to apply toward the new treatment? How should I talk to my current dentist to get the money back?
Thank you,

If you have been “paying as you go” with the invisalign treatments, you probably cannot get anything back. You could have a talk with your old dentist, saying that since the treatments did not work, is there some sort of warranty that he (or invisalign) puts on the treatment? But my guess is no.
If you have paid ahead with the treatment, then you should be entitled to receive back the portion of your payment that has not been used.
My best guess is that you are back to “square one” with the treatment. Could your old dentist do the braces? Maybe you could talk him into cutting you a good deal since the first treatment didn’t work.
I have no expertise in this area. This is just a guess.
get a lawyer and ask them.