Send it back for a refund.
Send it back for a replacement.
Start making discount demands.
An offer of a reduction in price is a goodwill gesture, probably the easiest all round for both parties (and 20% off for a wonky foot feels generous to me). If you ask for more and they say no, what do you plan to do then?
If you buy something new you’ve a right to expect it in new condition, not damaged. How much the damage is worth to you in terms of how much it’ll piss you off vs how much you think you can milk them for, only you can decide. Personally I’d be kicking it back for replacement as I’d assume it’s been dropped and I’d have no idea what internal damage may have also been sustained at the same time.