Spar Dunnde with poor customer service

Spar Dundee has once again misled me as a customer with their highly inflated prices. The product I was buying had two different types and prices displayed next to each other. I took the cheapest one and when I paid, I was told to pay the high price. This was reported to Paul the manager that refused to give me his surname and he refused to assist saying there is nothing he can do. Clearly this manager was not trained on how to deal with customers and Spar need to either take him for a refresher cause or disciplinary.