Unprofessional Service

We went to the Builders Warehouse Riverhorse in Nandi Drive and requested the Staff for ready mix cement and they provided us with Builders Plaster Mix. We queried this with the staff if this was correct of which they confirmed. I purchased three bags and when we tried to used it , it was just bags of sand, not cement. This is totally unacceptable, and I need them to correct this by delivering my bags of ready mix cement as I requested to my home.