Is there anything I can do about this? Can I maybe repair it, get it replaced? The thing about dents is that no matter how minuscule, they are extremely noticeable when you hold the thing all the time. 
If you’re good at mixing colours, you could buy some Sugru, mix a color that is identical with the OP-1 body, and apply it in the dent. Dunno, it might work?
Is it an actual dent or just scratched paint? You could try using a car rubbing compound VERY carefully with a qtip to try to buff it out. You could email TE and ask for the pantone of the paint and buy a spray paint then touch it up, or try some very fine abrasive maybe a fibreglass pencil to see if the blemish can be removed that way. But all of the suggestions depend on the nature of the damage so delete as appropriate or ignore completely!
Dent the rest of it, get it all relic’d up like an old guitar then it’ll look badass.
If it came dented from TE then you are surely entitled to a new one.
I’m with JohnSmith. I say add a few punk stickers/sharpie graffitti and head toward uniqueness.