Unauthorised debit orders

There is 2 debit orders that is deducted from my account, 1 for Uassist of R139.00 and 1 for Urewards R119.00. I've cancelled it from my bank because I have not authorised for these deductions. When I called their call centre in December, I told the the lady who assisted me that she must go back and listen to the recordings as I never authorised this. Again in January and February month the debit orders were deducted from my account. I’ve tried to call them since January on the call centre number, but to no avail. I’ve contacted my bank and they cannot assist as they change the reference number every month in order for the debit order to go through. What to do??