Overcharged without explanation at Levi's store

I purchased a pair of jeans from Levi's Springfield Park, Durban. The store manager, who was the attending cashier. Overcharged me. When I alerted him to the over charge, he ignored me. I asked again as to why he over charged me and he ignored me. I asked for response, all he said was, " I'm sorting it out" in an arrogant tone. He refused to explain the overcharge on the item. If this is the attitude Levi's is providing to its customers...Levi's should be boycotted in South Africa