Misstreated

Yesterday the 22 May 2019, i was at Heritage Mall by Leach Pharmarcy to buy my toiletries. On the shelf i saw Epizone cream on special, it was very cheap i decided to buy it. when i got to cashiers it scanned different price than what it was on shelf. they refuse to give me at the price i saw on shelf telling me that its not that price. i decided to go because they called different memmbers of the staff and they were very sarcastic. my concern what it i didnt check the till and assume i paid that price, how many customers are at disadvantage.