being ill treated and embarased by shop manager

I pretty Mvimbi went to shop at the sweet hyper on the 23rd March 2016. I wanted to buy oreo buscuits. the labelling was very confusing, labelled as 12x3's for R19.99 I took 3 boxes and other 2 customers they took more, but when got to the till we were told that each box is R19.99 .we had to turn them back and I asked the lady at till5 why is like that, she said she also tried to notified the shop owner but he didn't want to listen. So I went to him politely and tell him about my experience. He said we cant read and this is his shop no one come to his shop and demand anything, shouting on top of his voice, everyone stopped and paid attention to him. Then he said he doesn't have time for me and asked the security that I'm escorted out of his shop and they made me hold the parcel that I bought they took away the basket. I've never felt so embarrassed and so humiliated like that