Extremely bad pricing and service

Builderswarehouse in Florida Glen is the worst of the Massmart Group. I was trying to buy ready mix concrete from them however they are charging R55.00 per bag whilst the Builders down the road in Strubensvalley charges R40.00 per bag for exactly the same. I have queried this instore and was advsied that it is different suppliers which does not make any sense. They are all packed in the same bag with the same branding. I have phoned them and were treated to the fact that I am idiot by quering this since all stores charge different prices. Once again I feel this to be a bull**** story. I therefore demand that a SENIOR MANAGER or higher contact me and explain this indiocy to me. My number is ***. I expect an answer within 24 hours.