Different price on item to what they charge

Went to fishing specialist goodwood to go buy some tackle. On my my arrival there was hardly no stock and the 1 item i bought was charged differently at the till to what the price was on the item. I only realized this when I got back to work. I sent a photo of the price on the item and the price on the till slip to their Facebook page. They responded and said they would refund me the difference which was all fair and well, but then they blocked me on their Facebook page because of the placement. Not cool. For those who are going to buy by them, make sure that the price on item and the price you pay is the same.