Bad customer service

I am quite disappointed in your staff.<br> Saturday the 25th I bought 6 items and 3 of them were on sale thus automatically qualifying for a buy 3 pay for 2 voucher and my total amount was R834.01.<br> Mon I went back to exchange 4 items for different sizes (same price mind you) and only 1 of these was a sale item.The lady assisting me instead of exchanging the items she does a refund and then a new transaction on the items I wanted exchanged.First Im told its because I didnt have the rewards card when I went back to exchange.<br> Following day I return with the rewards card and then Im told its because I dont have the initial receipt.Upon my fourth return to the store Im now told to pay in more than the initial R834.01 because I now have only one item thats on sale thus the voucher is no longer applicable.<br> I went in for an exchange and yet Im refunded?And the store manager claims that she cannot do anything as she wasnt there when the staff member did the refund.<br> So now what should I do?