You only pay for skins that are bought. If a purchase fails, your money comes back to the project balance automatically.
Failed before anything was bought
If the offer was gone or the purchase failed before a skin was bought, the hold is released. You see Hold released in your balance history and nothing is charged.
Bought but not delivered
If the skin was bought but never reached the customer (they declined the offer, did not accept it in time, or the trade was reversed), the amount the market refunds goes back to your balance as a Purchase refund entry. The purchase page shows what was charged and what came back.
Still checking
A purchase in Checking keeps its hold while we find out what happened. It ends as delivered, failed or refunded on its own; you do not need to do anything.
Try again
Fix the cause first, usually a new trade link or a customer who cannot trade, see Purchase statuses and what they mean, then buy again.
Something looks wrong with a refund? Contact us through the contact page with the purchase ID (it starts with pur_).