Wrong Cornice delivered

I went to CashBuild Tsakane to buy ceiling material.They delivered all the items but I didn't verify if what was delivered is genuine,instead they gave us the wrong type of cornice material was suppose to be polystyrene instead they delivered the hard ones.We couldn't even glue them they kept on falling of.I am truly disappointed that we ask for something specific and your employees do as they please.Now it is a waste of glue and Cornice