Man, whew, you sound like a nightmare customer. The service advisors, technicians & service management all get pay incentives(or decreases) based upon those surveys you tanked. So it’s definitely plausible they fired you as a customer based on that. You can’t fire off terrible reviews & then still expect them to give you top notch service, or any for that matter. The tensioner on that vehicle is made of cast aluminum & is “pitted” brand new. All OEM GM belts are “dull” brand new, so no slick surface, to not make noise. I would do a self evaluation, make some changes. There is no “area manager” GM dealers are all privately owned. But I would chalk Imperial up, you’ve cost them enough money already I would ascertain, firing a customer is last resort.