MBD. The calls don't stop.

For several months we have been receiving phone calls and messages from this company regarding an alleged outstanding account with MTN. All our efforts to explain that the company denies that we are indebted to them have been in vain. They call incessantly. They are extremely unprofessional and would throw the phone down in your ear. Sometimes they would call and when you answer nobody speaks. Obviously charging MTN for these calls. There has been no response to e-mails to set the record straight. MTN tells us ignore them but it does not stop. One cannot win with them it seems.