Telkom does not want to refund my money

I app**** for a Telkom wifi router at Centurion mall in September 2014 and everything was successful. my residence showed coverage in their map, but when i got home, i had no coverage. i went back to Telkom and they sent through a technician who checked and and confirmed that i don't have coverage. they sent a second technician, who also confirm that there is no coverage at my residence. i returned the rooter within 7 days and they confirmed that my contract was cancelled. but i got debited the amount equal to the value of the wifi rooter. i queried this with them and they asked me to send them a receipt that proves that i returned the rooter, and i sent them the receipts, and they promised to refund the money and i still haven't received anything. i followed up with them on twitter and they kept asking me to email them my statement for refunds and when i do, i don't hear anything from them. i have emailed my statements at least five times to three different emails that they provided and their response is they will refer my query to a billing team. its been over a year now and i need you to refund my money. <br>