RSAWEB must fall

I actually want to give -0 stars. I wanted to change ISP, but RSAWEB took too long and I decided to stay with my current ISP. I have never received their router or used their services, but they keep sending me invoiced and statements every month and debiting my account. I have asked numerous times for them to cancel and delete me from their system as I have never used their services. It is as if I am being ignored and they just keep on billing m every month, what for I really don't know. I have made use of ALL their communication channels to cancel, but with no success. I now have to transfer my money from my account before the 1st of each month, so that their debit order can bounce. I don't know what to do anymore to get them off my back and stop billing me for nothing. I have never had a contract with them or used their service.