Transmission problem
1992 BMW 735 Automatic

My 1992 BMW 735I stopped running one day took it to a shop they told me I needed new trans...they rebuilt the transmission put in new torque converter new fly wheel and flushed trans cooling system, they drove the car about 4 miles and when the car got hot transmission stopped working want move in any gear.... the moter still is running but car want go in any gear plz help i have had to pay alot already and they dont know what else to do....