Had new transmission installed a week ago now having severe electrical problems

I had a new transmission installed a week ago (paid 3000) for a new one they replaced it and changed my transfer case fluid. Well now my drivers seat went out so I can’t adjust the height to the pedals. Both my passengers side windows either are stuck up and ones stuck down. The right door in the back always says it’s ajar when it’s not, my back windshield wiper does not go off anymore it runs constantly, the service air bag light is on and also my truck always is going into 4w drive low which doesn’t make the best for driving I just don’t know what to do. I literally just had a new water pump installed, new belts and hoses, new battery, new tires and brakes and I don’t wanna feel like I’ve wasted my money on this thing. And I’ve paid for all this in less than a year. Very frustrating as I need a vehicle since I’m a single parent. It’s also not fun driving around with a plastic bag over the back window since it’s raining. This is a 2003 Chevy Tahoe with a 5.3 engine

Did all this electrical hooey start immediately after the transmission was installed? Or a few weeks later? If it didn’t happen immediately, it is pretty much impossible for the transmission to cause any of this. If it happened immediately then it is possible the installer didn’t reconnect the ground wires.

So we know it is a 5.3 V8 Tahoe 4WD but know nothing else about it. Mileage? Did you recently buy it? Was it a flood car (salvage title)?

Since you don’t sound like the DIY type, take it into a good independent mechanic (not a chain) and expect to pay for fir his time finding all these problems, let alone fixing them.