Problem 1, I’d take it back your dealership service dept and tell them to fix it. This is a GM problem, not the dealership, not Onstar……..
Problem 2, if you the charger install through the GM program then it a GM problem again that the are shoving off on someone else. Its bs that you were told just reset your breaker everyday.
Problem 3, GM has a number of different cables at GMC.com, click on shopping and EV charging
