Terrible Supervisor service & false accusations!

I went to the Mr price store today to purchase a few things,with me I had a paper bag.after my purchase I was stopped by security to check my bag which I found odd because there are 100 other customers who were passing and not being checked,soI refused and called the manager as I have spent over 500.No Manager came to my complaint instead a verye rude supervisor accompanied by other supervisors came and attacked me and said all horrible things including the fact that I must not come back to de the store.my question is,how does one treat a paying customer with such disgusting attitude regardless of where they work because at the end of the day my purchase pays their salary. The fact they could scream across the shop with other customers being present shows,they have. No respect for clients and their jobs.it's a disgrace to appoint such people who act like hooligans when approaching matters