Returns not accepted

I bought a few items last week at the Riverside Mall store. I have unfortunately misplaced the slip, and wanted to exchange 1 item. I was told that they can't assist without the slip, because it was a manual transaction! I still remember the dates.. surely something can be done to assist me with the exchange? What am I expected to do with a clothing item that I can't use?? Even worse, when I enquired if I couldn't get assistance from their head office, I was told that it's even worse; nobody would assist. Couldn't get contact numbers from their website; and Facebook message was ignored. I fell in love with this shop when I saw it last week, but this whole experience put me off completely. Disappointing!