Call Garmin support. Tell them what happened and see what they say. Maybe they'll send you a refurb'd unit, maybe they'll won't. You'll never know if you don't ask.

A screen damaged a little bit might be just something that will get worse over time. My Edge 500 from circa 2010 still works, I expect my Edge 530 to still work in 2030. Providing I don't do something to damage it.