HVAC control unit replacement

I've been trying to replace my HVAC unit controller but all I can find is Dorman selling them. It is the automatic version. I have tried 3 different units and had to send them all back because they show they're set when I run through the setup, but they just don't work right. Auto doesn't adjust from heat to A/C right. The vents don't change from A/C in the dash to heat on the floor, nor when you press the defrost button does it change. You have to press the button that controls which vents are in use manually to set which vents to come out of.
The settings show my truck is to set to 2 and it shows that once I run the setup, even if I repeat the setup. The light stays on right for about a minute then goes out, but it doesn't work right.
Dorman sent me through the steps twice with each unit when called and they will not work correctly.
Also, the new Dorman units have LED lights that are MUCH too bright compared to my other dash lighting and if you turn those down the rest of my dash lights are almost, if not completely out. Irritating to say the least.
Anyway, are there any other companies you can recommend who might sell the OEM GM version unit? If Dorman isn't doing right and there isn't another replacement then I guess I'm going to just have to bite the bullet and use the old unit without any lights and that, sometimes when you least expect it will turn on the heat when it's hot outside and ac when it's freezing outside.
Oh, and I've changed both the ceiling unit and inside the blower housing unit those little sensors.
Help! Lol.
Thanks.