id take it back and tell them to fix it, regardless whats wrong it, you have a warranty, they have to honer it or get sued. you can get all your money back if you sue them. as they sold you a 3,000 tranny you did not need. or re built it poorly, one or the other.

remember they told you it needed to be rebuilt. and then took your money. its on them now 100%. where i come from thats called fraud. selling a 3,000 tranny and having the same problems as before they got it. if your gonna charge 3 grand it had better be fixed.