Refused to ring up the price that was in the shelf and not too friendly

My husband wanted to buy pots for plants and the price on shelf was marked R50.50, so he took and as he got to the till they said its over R100 each. To which my husband took a pic and showed them the price and said sorry that is incorrect price and refused to give the client the price as per on the shelf??? What tipe of business is this then... not too friendly either