Bad Service by Manager and staff

I bought a DVD box set series of Law and Order at the store, but on opening the purchase at home found a different series inside. I went straight back to the store and asked the staff standing around to assist with the problem, they called the manager and she told me to go and stand in line and a cashier would help. The manager was totally dismissive of me and the problem. They did not offer to order the correct item and after causing me to lose my temper and start swearing, I asked for a refund, which I received. All this time the manager stood behind the cashiers glaring at me and muttering to her staff in an African language. This behaviors was totally unacceptable, even if I had lost my temper at the inefficiency of the service. All in all, it took 4 different people to deal with what was actually a very easy problem. I have noticed a steady decline in service and management at this store over the last few months and although I only live a block away, I will not be returning there again.