All i can say is... why did you invest in a no name brand? Noobs on this forum complain all the time why their wallmart shotties or DPMS Panthers (shudders) dont work for more than a couple of months at best.
All have one Answer: Take your brain next time you go shopping and dont be afraid to cough up money for the good stuff.
Now i believe that Bell M9 is a clone of the HFC M9 which in turn is a clone of the TM M9. And its not even a 100% same clone.
So.. most you could do to repair your sh*t gun is to start using TM (Tokyo Marui) parts or cannibalise a beater HFC M9.
Either way your money is sunk.
Also Next time, dont complain about your sh*t gun fallling apart.