Disappointed and hurt customer

Today I went to PEP in Jakaranda Mall in pretoria, I saw shoes that were on mark down for R24.99 and was so happy for that low price. I took 2 pairs and when I got into the till they told me that its a markdown mistake, imagine the disappointment & hurt. There were about 10 pairs of shoes with that same price, what kind of mistake is that. so now whose fault is it? What happened to the notion of "you pay the amount you see". Im so ****ed and disappointed at you Pep as a your loyal customer