Buyer asked to cancel but refusing to do it themself

Frustrating situation here! I put something up on vinted and within one min a reseller account had purchased it, then immediately messaged me asking for more photos which I provided. They then said they wanted to cancel. I said fine go ahead. They told me I had to cancel not them. Essentially they don’t want a negative review for cancelling an order, but I feel they have messed me around so others deserve the warning they do that. I told the buyer they need to cancel and since then they have ignored my messages. Vinted support have of course been 0 help. Anyone else had this? Guess I have to just give up and cancel the sale? Just hate how they get to mess me around and not have any backlash for it