This happened a few times to me and there is one solution that does work in my case, but takes a lot of balls.
In my case, the seat wouldn't recline back after I reclined it forward. After playing with it for a while, I got really annoyed and made it go to a near-undriveable position. Got home, posted on here, took the seat apart, found that the little motor thing jammed ever so slightly and would only rotate one way. Put seat back together. It worked.
Next time it happened, I was knowledgeable and did this:
*****
I reclined it forward, checking every now and then if it goes back. Eventually, I reclined it a looong way and it began going back at this point. Once it goes back, keep holding the switch and it goes back all the way.
*****
This has worked for me on the 3-4 occasions that this has happened so far. If it fails to work though, you won't be able to even get into the car, so apply this at your own risk