No refund

I bought some things from clicks Thembisa in December 2014 and they double charged my card because their teller or speed point ill functioned while my transaction was being processed. I went back with my back statement to prove I have been double charged and requested for a refund but I'm still waiting. I have phoned them several times and their manager keeps saying she will phone me back but no one has phoned me back since. I keep incurring the cost of having to phone them but they never sort out the problem or phone me back. May I please have my refund clicks