Dunno who "they" are in your tale of woe and intrigue, but I am sorry you experienced this. Obviously not a "they" who know what they were doing.
May I suggest a Chevy dealer might be a better choice?
I successfully navigated a similar situation a few years ago when I bought a 2 year old BMW X5 to be our tow vehicle. I did my research, and found that BMW sold a hitch, wiring harness, and brake controller for that very vehicle. But the installation charges were high, and the costs of those harnesses and controller seemed excessive. My local RV guy said he could do it for about 1/3 the price. But his hitch installation price did not include the removal of the rear bumper and bumper cover necessary to attach the hitch to the studs BMW required the hitch to be attached to, so his estimate was bound to be low. And his wiring harness called for splicing in wires under the dash and to the light sockets in the back. The BMW has a socket already installed you only need plug into, but it's located in the right rear fender well.
I had mine done the right way, and it has been trouble free. I've spoken to others who went the cheap way, and they've had nothing but trouble. The car's computer freaks out, the lights don't work right, the brake controller doesn't, it all adds up.
So let me add to the OP's warning: modern vehicles don't always respond positively to "the way we've always done it." Do your research. Find someone to do the job right the first time. Even if it costs more up front, it is a LOT cheaper than doing it wrong the first time, and then having to pay for doing it right later, and that's not even counting the sheer hassle of dealing with a bad job the first time around.
BTW, mod notified this is in the wrong forum.
