MTN billing incorrectly

Hi there,<br> <br> This is the second time that I am complaining about MTN who has been deducting insurance off my boss's accounts which we have tried to cancel since June 2015. I have all the documentation that he signed at a branch cancelling this in June and he was charge up until Feb 2016. After loads of mailing (because you can't call, their lines are permanently engaged) I finally got a reply from someone who I was hoping could help. This person did help to a point by removing the insurance from my boss's invoices but now the issue of refunding my boss for the months that he was incorrectly billed has not been resolved. We got a refund for 1 month of the insurance that was charged and after that I got one mail reply. I asked for a number to call to try and speak to a senior or someone who could try fix this and I have had no response from my mails I have sent since. <br> <br> My previous complaint got a reply from someone called Mark who works at MTN. He said that he would be in touch and I have not heard from anyone at MTN. <br> <br> Thank you <br> <br> <br>