Mtn vouchers

Please assist me I purchased 2 R100 rand mtn vouchers on the 5th off May they had technical issues and would refund me with in 7 working days because I never received the airtime but my money was taken off my bank account,I logged a call after 10 working days because I was not refunded I tried to go to the stores and nobody can assist me it's now the 15th off June and I still never received my R200 rand refund when I call the call center nobody can assist me I get told that I can only communicate to the through email not 1 salesman or supervisor or manager can assist me how is this possible that they can take money and not deliver any service.should