Builders are ripping the public

This is not the first time but in fact the third time Builders have ripped me off. The price on the shelf does not match what you actually pay at the till point. After paying for my items I went back to the shelf to check the price and found a difference. I requested to see a manager but to no avail could they find one. The cashier called at least 4 numbers and I waited 10 minutes but they could not locate the store manager on site. I left the store very unhappy but wish to name and shame this Hardware Store for their dishonest way of doing business.