Withdrawals cannot not be completed

Hello, I have tried now numerous times to make a withdrawal from my verified account ( there is even a selfie). The problem is that all my efforts to withdraw are either declined or they show up as completed and I have not received the money then it is refunded back in my account and it does not show up in transactions. Support and email help explains it with invalid IBAN numbers. I tried both my banks IBANs and it is the same issue every time despite that my IBANs work everywhere else. Bettilt says that I should contact my bank which I did and the bank says the issue is on Bettilt's end.

I also tried other withdrawal methods and they don't work. Their most common explanation is ''Provider issue'' and that I should make another withdrawal but the result is always the same.

So the common course of the events is :

1) I make a withdrawal which is declined or shows up as completed,

2) I have not received anything and ask what is the problem and they come up with the excuse of provider issues and refund the money in my Bettilt account and ask to make another withdrawal,

3) this happens again and again.

And now I have some bonus which I do not want on my account that they wont remove and this is blocking me from making another withdrawal.