Receiving statements for services which wasn't approved or required.

I coincidentally found an email stating that we are owing Trudon more than R3000. This email was sent to an email address which has not been used for years. We have not agreed to the Services for which we were charged and have cancelled our telephone line a long time ago. It is therefore unfathomable that we would be listed in the yellow pages if we do not even have a landline. The address on the statement is also not our address. Yet, they informed us that we are going to be handed over to the attorneys for collection!! I have tried to contact Trudon Telephonically without any success. I have sent emails to every address for Trudon which is reasonably possible of assisting me, there is absolutely no feedback!!!!