instrument cluster glitches,no turn signals, an brake lights

Bought the truck brand new had to order it wait a week before receiving it, looks awesome the ole lady was so happy. " her first truck". there were scratches on the side and they offered 3 free oil changes... deep scratches, luckily we work our trucks and have large dogs not worried that way we don't cry the first time we give it character. the instrument cluster started acting up within the first 500 miles #1, Ballas Buick GMC said it was low voltage bc it sat on the lot.... we had to wait a week to get it bc it was a special order. #2 went out in the morning to start it, dead battery so I charged it up an called them. they said it was cold out... well my 04 dodge 1500 started right up, 2014 dodge, an 2000 7.3L started right up! #3 acted up around 750miles doing the same thing dropping the spedo, rpm, fuel gauge. Ballas replaced the BCM said that was the issue. #4 acted up just the same as the last couple times now we have 1500miles on it, Ballas replaced the HVAC computer said that was the issue. Within 24hr it was back into them yet again why will they not just buy the truck back!!! I have been in contact with GMC customer service, nhtsa, att gen. look on youtube.com an search zach pawson there are a bunch of vids of my problem. we don't even have enough miles on it to change the oil, out of the 3 months we have owned the truck we have had it for maybe 20 day.