Spar don't care about they customers

I went at spar on Sunday on 11 may to get some chips it Was around about 10 in the morning when I got there buy the chips department I saw the hole bay of chips Doritors they had a price of R17 pointing at them so I took one went to. A cashier to pay when the cashier scan them only to find out it was R25 I told there cashier that I saw them it was written R17 she said to me can't you read it onother chips not Doritors but they made a mistake, I was very disappointed the way that cashier handle the situation and even when I ask for ther supervisor she pointed onother cashier said this person can't read it onother product it not Doritors that price, but was not my mistake and as a store they must not make mistakes like this and they didn't follow the consumer act and the way they treated me was like am a stupid, am very disappointed with spar and I will never shop at spar again in my life, and I will also tell my friend and family not to cum at spar for my bed expiring I got from them, the cashier name is Philly