Transmission and u-joints issues not being resolved

In June, I had my transmission rebuilt in my Suburban for $2,000.00 with a two year/50,000 mile warranty. The shop that did it took 2.5 weeks to complete it. Originally they said it would take three days. Also, the guy who rebuilt it is one who rebuilds for several shops in my town. When I got it back, it did not shift perfectly and had less power than before. While gently pulling away from a stop sign, I felt the transmission slip and then heard grinding with 20% power in forward gears. I stopped and had it towed to the shop. They said it was bad u joints and that the transmission “checked out on the scanner.” The check engine light was not in yet. So, I changed the u-joints and kept driving it, knowing full well it was the transmission. It started slipping, the check engine light came on and then there was a loud pop under the car. I again lost all forward gears, as I had in June. I stopped and had it towed to the shop. That was on October 28th. The guy called me on October 29th and told me it needed to be rebuilt again or replaced with another unit the guy who does the rebuilds had rebuilt. My Suburban is still sitting in his shop parking lot with the broken transmission still in it. He has given me multiple excuses. It has been almost six weeks. Is there anything I can do? I do not have the money to just go get this old suburban that does not run and throw another $2,000.00 in it getting the transmission rebuilt at another shop. Do you have any advice? I live in Denton, TX.