This car I love but I hate at the same time, good thing I have a spare car I can use. When I get like this

I just switch cars because no matter where I go or who I ask I don't get an answer. I had a local mechanic do transmission service (change fluid & gasket) at 110kmi. The car seemed fine for awhile. Sometimes the digital display for what gear you're in blacks out (the colors reverse), then after a few miles it goes back to normal. Is that a sign of something wrong or just a short? When I first start driving or after I stop & continue I have to hit the accelertor hard to get moving but after that first initial acceleration it's fine. I'm afraid that I might be ruining the trans if I keep driving it. I tried calling the dealer & asking them but they don't help you at all. They want you to bring it in & charge you diagnostic time & nothing is ever fixed, when I tell them problems I'm having they say they don't see it charge me the time & nothing is ever resolved. My service light has been on for 2 years I brought it in 4 times for that & they say they need addtional labor hours because the machine didn't pick anything up. Is that my fault? Why should I pay extra if there machine isn't working. They are never of any help. My way of fixing the service light problem is by not looking at it. It's funny that everything else on the car breaks on the car but the light is still shining bright, that will never burn out.

Can anyone help on my trans problem? If it is a trans problem.
Thanks
Diane