Overcharged

Went to pick and pack Newmarket for the first time today to purchase my greens for supper, i 1bought everything I needed and went pay the amount of R292.24 for everything, but when I get home I realize that I was overcharged, when I checked my receipt I found out that I wasn't charged the R15 for 300g mixed leaf salad as advertised, but was charged R94. 99 for pnp extra virgin olive oil that i didn't purchase. My purchase was made at 13h32 and the cashier was Mammilisi Mbhele, Tried calling the shop for them to assist resolving the matter but they're phone seems as it's not working. I hope I'll be able to get assistance on this platform.