Rudeness in Retail @ Retail Park

Yesterday my store was counting stock take at night and realised I had left my earphones at home. So a colleague and I went to Cash Crusaders @ Retail Park were I had bought iPhone like earphones. a few hours into counting I decided to use my new earphones to find only 1 side working. Well that was the least of my worries because I that I could exchange the defective product for a working 1. After count today I asked 1 of my staff to go exchange it she came back saying they refused, I couldn't understand why they would refuse taking back their product. When I got there I told them that I would like to return the item for one that is properly working. I was approached by a guy named Athenkosi (nametag) and he was very rude to me on the sales floor by the till points infront of customerd, saying I won't be getting new earphones and that's final. His tone was aggressive and if I had entertained his attitude it was going to end up in a fight, well him beating me judging from his tone. I'm a store manager dealing with customers all the times and that's not how a paying customer should be treated. I wasn't asking for a lot I just wanted working earphones but he acted as if it was his backyard. I'm very much disappointed and disgusted by the the service. I am planning to open an assult charge against him and I won't take this lightly. I'll be also taking this up with Cash Crusaders' head office, I need to know what the company is going to do about this matter. I was actually planning to buy a sound system for my studio from them but if they can't appreciate my R50, they don't deserve my R5000 I would've spent to buy the system. Well done Cash Crusaders Retail Park, you've lost a customer.