Advised them not to call me again no agreement

I don't know how many times I have advised the consultants at Creditworx not to contact me again as I do not have an agreement with them, but instead they keep on calling and sending me annoying sms on top of that they can't even proof that I have an outstanding which they forcing me to pay for. I am really annoyed now as this has been going on for months now. Please please I am bagging you to please stop calling me and to remove my details from your system. I am being very polite but won't be if this doesn't stop