When you start a transaction with a credit/debit card, the pre-authorization of funds is performed by the Paybis payment processing partner. Pre-authorization is a hold of the amount you wish to spend on buying bitcoin, i.e, and it reduces the balance of available funds in your bank account until the transaction is completed or canceled.
We advise you to start a single transaction each time and complete it before starting a new one since the funds are pre-authorized for all of them. In case you leave the transaction unfinished or cancel it or it is rejected from our side due to internal policies, you will not be able to access those amounts until they are released into your bank balance. We void payments immediately for unsuccessful transactions. For most banks, the void of a pre-authorization happens instantly and funds return to the payer's account within a few seconds. However, certain issuing banks process "voids" much slower, so it could take several business days depending on the issuing bank, but usually doesn't exceed 14 business days.