Terrible service by Management.

I went into Pep Stores Durbanville asking for a manager, I then asked the lady witch had an attitude upon approaching me, whether I could exchange an item that still had the tags on but I unfortunately misplaced the slip witch her response was just no with an extremely bad attitude. I would like to know what I should do with an item that doesn't fit. I have in my life never ever had such bad attitude at any Pep as today. I myself work in retail and believe my area manager would chase me away if I had to approach a client like that.