double billed

I went to Mr Price in Dobsonville on the 24-04-2015. I purchased goods to the value of R 209.97. The was a problem with the machine, I did not get a slip or even a copy or print out but i got the notification form my bank advising that the transaction went through sucessfully. i was told that the transation did not go through so i was forced to swipe the card again or leave the store without the iterms.The cashier called her manager and i was advised that they cant trace the transction . The manager by the name of Janette said i must leave my details at the store and she will sort it out. I have been patiently waiting for her call and no luck. i called the store again and she is not getting back to me. I have a statement showing that my account my double debited. Please assist by sorting this out for me