Poor service - Cement and grout poor quality

Found our tiles at National Tile Traders and decided to buy the cement and grout from them. They were much cheaper than CTM but we decided to get everything at one store. Our tiler started tiling, after two days the tile cement was still not dry. My husband went to National Tile Traders and spoke to Alfa and Margaret on more than one occasion (at the store and on the phone) complaining that the cement did not want to dry. They said we should wait another day which we did. After day 3 we decided that we had to fix the problem ourselves as we did not get any feedback from them. All the tiles had to be lifted, we went to CTM and bought new cement and grout. This amounted in us spending double the amount of money on cement and grout. After numerous phone calls the branch refunded us R47.90 for one packet of grout. I want a full refund on all money spent on cement and grout R770.90. I have kept all the slips to prove that I had to go and buy new grout and cement. NOT A HAPPY CUSTOMER !!!!