Wrong pricing and bad attitude

god day, I went to a shoprite store in randbrg because i wanted to buy custard for my sick child. I was released early from work because my child was sick and wasnt eating well at day care. I decided to go to shoprite because I know they have great prices and when I check their prices for a big box of long life custards there was one prices R13.99 and one didnt have a price. I took both because i wanted to check the if the one that was appealing to me how much was it beacuse it wasnt priced and it the price was resonable that the R13.99 one i would decide whitch one to take at the till. The lady at the till told me the other custard that was R13.99 at the shelves was R25 when she scanned it and the other one that i had was R19.99 and i ended up taking the R19.99 one. When she queried with her colleques some laughed and said how can this customer expect such a custard to be 13.99 and one went and checked on the shelves and it said R13.99 but nothing was done about this. Because i was in a hurry to my sick child i ened up paying R20 for the custard. I find this very unfair and nort proffessional for shoprite store.