Very Frustrated

I went to Festival Mall on the 31st of January,2016 which is very far from my house, where I purchased 3 tops from Fashion Express. On the 10th of February, 2016 I went back to Fashion Express to get a refund for one of the tops because it was unsuitable. Joyce assisted me she handed me a slip to say she has refunded me I still had the tag on the top and my slips and I also paid with a Debit card so she just put my debit card into the machine for a second and said the money is now paid back into my account. I asked her if she's sure and she said yes, I checked my balance before I went there and when I got home I checked my balance again and still the same I called FNB and they said there is no sign of the refund yet, I want my money back please!!! Joyce there had me waiting for about 3 minutes because I thought she would give me money out of her till and then she asked me what was the matter, only then I realised I have been standing there for nothing and that according to her the money has been paid onto my debit card, how can Edgars give me R 500.00 out of their till on the same day and you guys have this ******** insert your card for 3 seconds thing, I NEED MY MONEY BACK!!!