This separated “getting approval” from “paying” and the insurance company had no say in the parts. But I then went back and directly asked the insurance to pay this difference, as this is how the vehicle was before it was hit by their insured. When they repeatedly ignored my calls and emails, I went up the chain of command, always documenting the chain of events beforehand, and repeated the request. I never got a straight answer, but when I went to pick it up, lo and behold, it was all paid for – the checkout desk said “nothing right”.
The lesson here is to tell them what you want, repeat as needed to get a response, go up the chain of command if that’s not the right response or they’re ignoring you, and generally make it clear that you’re going to cause they have a lot more hassle than if they just give in to you.