You can do one of two things.
Yu can send the buyer a mutual cancelation request. If he agrees the transaction is cancelled and you get a final value fee credit.
You should only send the request if you are sure that the buyer will agree to it. If the buyer refuses the mutual cancelation request,you can't open an unpaid item dispute. The buyer can still leave feedback.
You can also choose to open an unpaid item dispute against the buyer.if he them pays you ship the item. If he still doesn't pay you can close the dispute after 4 days and give him an unpaid item strike. You then get your fees back and the buyer can't leave feedback.
I would send an unpaid item dispute on day 4. If they do not pay it and get a strike, it may cause them to think twice before just bidding all willy nilly.
