Bad service

Bad service. I work at Craddlestone mall and went to Pick n Pay to do some shopping. Went in and saw Surf washing powder selling for R34,99 (price on shelf). I took it and paid at the till, then I checked my tillslip and the price I paid was R39.99. I told the cashier about the difference. She said it's R39.99, said nothing else and proceeded to help another customer. So I'm standing there like some damn fool waiting for her to do something about it but she ignored me. I was on my lunch break, checked my time and realised I was running late already and decided to leave. I feel it is unfair that I was ****** of my money that way, and please Pick n Pay must retrain their cashiers on how to help a customer with such a problem. Real bad service