I got backed into a few weeks back and took the opportunity to do a M3 replica front bumper cover. Kinda a silver lining situation I think. Wish I'd been lucky enough to do new lights!
Regardless I think you're within your rights to push for OEM stuff. Had you wrecked your own car maybe not, per terms of the policy. But as it's not your fault at all you should be put back to whole.
All insurance companies have good stories about them and all of them have bad stories. As someone in the industry... Be reasonable, if you get rude they'll throw it right back and they're the one writing the check. Plus they have more legal support than you. Don't be a push over but don't pull an attitude, it won't go well.
I tell people all the time, the handling of a claim is pivotal on 2 things, the type of day the adjustor is having and how you get along with them. Sad but true.