Telkom - No response

In February we received a Telkom Modem for Uncapped Internet however we struggled to get it working. It would go on and off. We first thought it was the line so put in a query but they said the line was fine. We received a second box and this also did not work. On the 3rd attempt, we went in to the Langeberg mall shop and the lady tried from her side but also couldnt get it going, We finally returned that modem as well. Since then every month I have been receiving invoices for the 3 modems + data... we are on MWEB at the moment with no problems from the word go. In March I requested a Credit and lodged an enquiry on my account . I have emailed the docs about 3 or 4 times with no response. I also lodged enquiries on their site. I get messages saying it has been resolved but nothing has. They are still deducting money off my account every month to date. I am at wits end. We have also been into the branch but they are of no help whatsoever.. they just keep telling us to email the docs.