Cash refund refused

So I purchased an evening gown on the 14th December, went and swop out the dress for a different size the next day. This was a cash purchase on my debit card. I was fortunate to receive a beautiful dress from a relative and decided to return the dress. Unfortunately with all the excitement in preparation of the event the receipt was misplaced or lost. Went to tygervalley store who informed me return to the store where purchased which is parow as they would have a copy and would be able to look up the details on their system. Just to inform you the tag is still on the dress. The "manager" comes forward and says, sorry we can't help you without a receipt. Didn't even attempt to look on the system. Now I'm sitting with a R700 dress I'm not gonna wear.

She still had the nerve to tell me why don't you give as a gift to someone...seriously.