If the damage was done in transit, then you need to refund the buyer and afterwards, seek compensation for yourself, from the courier / postal service ysed.
Ask the buyer to open a case for item not as described. You need to accept this in 3 days. If you want the item back before refunding, you need to pay for that fully tracked return postage and refund when the item is back with you. You have 48 hours then to refund.
Stick within those timelines, and your seller performance is not affected.
@sopkeul-4