What you're experiencing is a pending authorization or hold. Every time a potential customer attempts to process an order on any site online, the merchant must first authorize the funds, to be sure the customer has them in their account. Then, it approves or declines the transaction based on other factors.
Regardless of whether the transaction goes through or not, you will always see a pending authorization on your account. If the transaction fails, like in your case, you may see one to multiple authorizations pending on your bank/card account. Funds were not deducted from your account, they were held for a short period, and then disappear from your statement. These pending authorizations should fall off within a few business days, but that timing depends on your bank.
We are unable to refund the failed transaction, as we did not receive any funds to refund.
Please contact your bank to find out when the holds will fall off your statement.