Aamco Transmissions charged for services not rendered now(1 year later) wants me to pay again! Longview Texas

I paid Aamco 3500 to rebuild my transmission(so i thought) . It took me bout a year to pay it all off but i finally did and picked up my car.

A few months later my car is doing the same thing so i take it back to Aamco. Steve the owner doesnt even open the hood he just stuck some lil gadget in my fuse box and said it was fixed. Two days later back to same thing. 

Now a month later after not hearing from Steve or him telling me he has ordered the part needed, surprise my warranty is no good i have to pay for repairs.

Main thing that gets me he says transmission was orfered from somewhere else and their warranty has run out. But my receipt says i was charged for Aamco rebuilding my transmission. Money Scam