terrible service at woolworths trade route mall

I am so upset and disappointed of the service I got at woolworths trade route. Cut the long story short I was told that my transactions could not be found on their systems which happened on the 29th Aug 2015. I swiped for clothes which amounted to R750 I returned 1 item which when I wanted an exchange I could not find the right size and the was nothing that I liked at the store so I asked for refund,then they told me that they cant because I do not have a slip. Then I remembered that I neva even received a slip from the cashier which was having a chat while assisting me. I would like to know how do I swipe for goods with my cheque card and could not be traced on your systems? Tomorrow I am going back to woolworths with bank statement just to prove I am not a thieve! If possible I would like to return all five items and have my money back.