You might
1) Consult with another tranny shop. Have them do a test drive. See what they say. Stick to the facts with them...not get into how they're better than the other shop... (which sometimes happens). Maybe don't even mention who re-did it. Maybe it is working normally, or if not, perhaps they can give you a nugget or two of key information that leads you to a path...or you can go back to the original rebuilder and negotiate a resolution. Even if it costs you $50-$100 for a comprehensive diagnosis..doing pressure checks or whatever, it might be worth it. Make sure you know what fluid they used and any other key bits of info, before you go to shop B. Did they put in a new shift solenoid? What brand/type torque converter did they use? Answering transmission questions over the internet is real tricky. How long have you been driving it? Have you tried unhooking your truck's battery cables and tying them together overnight? Did they reset the tranny tune? Sometimes it takes a little while to re-learn too (usually a few days max).
2) Google search something like what you were describing in your first post, then put, Reddit, after the search text and it should search out the Reddit forums, hopefully one used by actual tranny rebuilders. Fine-tune your search till you come upon some tranny rebuilders. Find out what the tricks and gotcha's are on RFE's that you might have going on. There are also Ram and Tuner forms on Reddit that are a bit more specialised in some ways. Worth a try.
Do you know if the rebuilding shop used all/mostly OEM parts? Or aftermarket? Which ones were aftermarket? What fluid he used? I've rebuilt a few automatic transmissions (and manuals) over the yrs... I never had one that *didn't* work right afterwards or crapped out prematurely. A guy has to be real detail-oriented and not skip a single step. And that's the KEY. And even then, there can be the rare hairline cracks and worn item ya missed. A guy who knows his stuff shouldn't miss things but anything can happen, right? But I haven't personally rebuilt an RFE though. Honestly, it's not that difficult to re-do an automatic transmission, but there's a lot of stuff to get right. A little more detail oriented than an engine. But I can tell you for a fact that different brand fluids in GM's and Fords can make a difference in shifting. Lived it first hand.
