unhappy customer

I went to biloxy spur at Baywest mall to buy a meal with my spur voucher. It was a R100 voucher and I didn't know that I can't buy for less than R100 on that coupon I ordered a burger and later was told I can only oder something that is more than R100 I had no problem with that I told them I'll come back during my lunch time when I have decided what else to buy. When I came back a nice guy called Luyanda offered to assist as he was assisting me the lady who helped me earlier on jumped out of nowhere and started asking Luyanda about my order and if I was buying the same burger again and mumbled things I could not hear and she had an attitude. I ask her what she was asking Luyanda as I was standing infant of her and if she wanted to know something about my order she should ask me. She said she was not speaking to me. She kept on and on and I wrote on their store complaint book her name. This is a huge disappointment as I am a regular at spur and I never had this kind of attitude before. I will never set my foot in that store again