HV MAXX / won't move as used to

[neweuser]

1) When in the air, it runs fairly good. On the ground it'll hardly move. i rechecked all the soldering and seemed solid and good.
2) Gearing: 72/11, volatage: 14.4 total? 7 cell IB3800's.
3) After it has been doing this, ran hot, like i couldn't touch it, and thermalled several times. But when i first got it, I ran the 70/12 set up, ran warm unless i did endless doughnuts, or until I fried the slipper because it was too loose. Then went to the 72/11, then all XXXX broke loose. It stuttered a little, then got worse and worse! Now it hardly moves!!! I want to send it back!!!! Not sure where though...thanks guys! Any other advice?