MyGMC app stopped working 3 weeks ago. Now I find that do not have OnStar connection

I hate to say this but Welcome to owning your NEW GMC!!!! I purchased my GMC Sierra Denali with 19 miles, 2 years ago.  In the 2 years we have owned our truck this, as well as every other feature, has been and is a consistent issue; GMC is well aware of but refuses to acknowledge and recall! Personally, I have had at least 4-5 replace modules, we have had engineers out and replace 5-7 different modules for various issues! After spending the majority of my time at the dealership and on the phone with various GMC Customer Service agents/management, I had to take a break at it was consuming the majority of my time. Since then I have kept a running log of each issue, while basically overlooking/living with it!