Sold an item on vinted but buyer received wrong item?

Hi all

I sold an item on vinted recently and it was sent via Relay. The buyer received the item but the order was suspended because they received a wrong item. She attached photos of the item which was a t shirt that I didn’t send, in a black package that had her address and name on it. This is definitely not the parcel I sent as I sent my item in a white bubble envelope.

What can I do from here? Is it possible that relay mixed up my parcel with somebody else’s? I have no use for the t shirt even if the buyer returns it to me as it’s not my item to begin with.