I wouldn't give them more than another try or so without investigating your state Lemon Laws. Your time and mental health becomes more valuable as you get older, at least I've found that to be the case.
In our case, it turned out returning the broken refurb was handled outside of the normal warranty group. "limbo" is the nicest way to describe the place we ended up in. The drone on the phone could not handle the return, a manager was not available and "someone" was going to call us back within 3-5 business days. Needless to say the last part never happened.