I'd like to submit this puzzle into the tactics trainer
Pawn takes bishop seems like a bad idea because white would then just take the g pawn. And queen to b1 check it tough for the same reason. I would probably try something like queen to c4 or b3. No matter what I dont see a win coming anytime soon. This problem, if it's true, would have to be rated over 2200. But that's probably because I have a rule to never try to see more than 4 moves ahead so if it's a mate in 5, I wont find it.
There is only one correct move for black to win. Can you find it?