Cosmetic damage and wear and tear isn’t covered under Applecare. It’s a service agreement, not insurance or a guarantee to replace any and everything. When I worked at an Apple store we did a few of those type of things under warranty, but usually only if we were already doing another repair on it, or if the person threw a fit. And you really don’t want to be the jerk that throws a fit. It really does ruin the employee’s day.
To have it done out of warranty would most likely be a Level 1 repair, which is about $320, at least when I worked there a year ago.