The bank did not authorize your transaction: adopteunmec

Good evening, my issue is as follows: I want to take the 1-month offer at €30 on a new Adopte un Mec account, but it gives me the message above: the bank has not authorized your transaction, even though there is enough money on it, and moreover, I have already used my current credit card for my old Adopte account, so I must admit I don’t really understand what the problem is. If anyone has a solution? Thank you in advance. ;)