Bad Service from a manager

Today I went to the Cavendish store to return a pair of jean that I bought on 30th June for my brother who stays in PE. He tried to return it there but they didn't allow him since he didn't have the slip. Went I went to the store today a cashier asked and listened as to why was I returning the item only now but then she said she'd have to speak to the manager. Then the manager came her name is Rachel, she didn't even ask anything nor was too greedy she just said NO when I asked why she became very very rude. I have had this account for more than 10 years I have never receice such treatment. Whenever I tried to ask questions she was becoming more rude even customers were watching us. The cashier had checked the item it is still on the system, I would understand if it is not and it wasn't worn even the price tag. But Rachel didn't even bother to check the item all she cared about was being rude to me. As I left the tills she and the other manager laughed very very loud.

I was there at the store last week looking for a flip-flop for my daughter a white gentleman was assisted with a similar case that I have he had the item for 5 months and was still new.

I don't know maybe the rules are based on race.