"If your auction already has bids, you will not be able to delete it yourself. If you open a support ticket we might be able to delete your auction for you. We cannot promise that we will be able to do it because it depends on the circumstances, but we will try."
I think worse case scenario is after the auction ends, the highest bidder (me at this point) requests a refund from you after 3 days. So sorry you have to delete the auction