Bad service and wrong pricing

I went to Queens Park in greenstone mall because they were having extra 25% on sale. Only to find out when I got home that the item where scanned with original price ( no sale no extra 25% ) I decided to went back to the store to be told that manager is off and they can't help me I must come back tomorrow. When I refused they called her and she told me that there is nothing she can do and if I want I can call head office . Is this the way Queen park treat their customers?