Poor Service!

I work in Brooklyn mall. I went to Mr Price Brooklyn Pretoria for a buy one get one free special. However I was extremely unhappy with a cashier Zwonaka's lack of service and unprofessional conduct treating me like a non paying customer! calling next customer whilst I'm still packing items I paid for! I want Mr Price to carefully assess this matter! I ended up not buying the pair of shoes I wanted thus no ssle for the store because of **** experienced at pay point! And I want a formal letter of apology acknowledged by management and Head office! Especially because I am in the customer service industry.