Just a thought.... when a transmission fails, it is common for small bits of metal to be distributed throughout the transmission hydraulic system, including the transmission cooler lines and transmission cooler. If the repair shop failed to clean the transmission line, replace the cooler (you can't successfully clean out the cooler), and replace the torque converter (some rebuilt transmissions do not come with a new torque converter) and that was the proximate cause of the repeated transmission failures, you may have something. They also could have misdiagnosed the problem, as the root cause of failure could have been a faulty transmission control module/pcm, or mis-adjusted throttle valve... of course all of this would have to be determined by an "expert", and thus would involve spending money without any guarantee of any return.