If this is the case, it is most likely that you have sent too little to cover the order amount. Please remember that you have to send the exact amount (not what you're wallet is saying is equivalent in Euro or other currency), this may also be the case where the transaction has the fee reduced from the sending amount and not added on top.
When this happens it will take up to 48hours for us to process the payment manually. A voucher will then be issued based on how much was recovered by us at the time of recovery.