Unauthorized Deductions on my Bank account by ProPay Systems

I have only recently found out that a debit order are being deducted from my account. After an investigation done by the bank they reported that the deductions are made by Propay Systems. i cannot recall that i ever gave authorization for this debit order. I cancelled the debit order but every month propay changes the reference number so that the debit order can go through. then i need to every month go inside the bank to cancel and reverse this. I need to every time pay a fee to the bank to stop the debit order and reverse the money. my most recent experience was that after stopping the debit order and reversing the money three days later the money gets deducted again.

i have contacted Propay systems and after giving them all the required info all they say is that they cannot pick up the debit order on their system.