the engine surges when driving it feels like the converter

A week after I purchased the car I noticed that the car's RMP's seemed to surge while I was driving it also felt as if the transmission converter would engage and dis-engage at highway speeds I took it back to car max they had a tech drive it and he felt it also, so they sent it over to a local chevy dealer ship they have had my car for a week they claim they checked the Transmission, differential, axles and the Computer and found nothing wrong. But I just spoke with my uncle who works for a chevy dealership and he told me they have had problems with the transmissions in the Equinox's for years I'm pissed I didnt notice this issue with in the first 5 days I could have gotten my money back from Car Max now looks like I'm stuck with a car with a known transmission issue that the manufacturer refuses to acknowledge or fix

The car feels like it is wants to stall out. also feels like it's in manual mode while driving and RPMs go up. took it to dealer service manager went out for ride with me, said he felt it and also mention he feels a vibration in dashboard. he said he knows what problem was that it is internal. took it in the following week they kept it for over a week transmission tech claims he can't find anything wrong. he talked to manager he claimed not to know anything. They claim there are no complaints and GM hasn't issued a bulletin on the problem.