Worst service

Good day

I write this full of disappointment and anger. I live in Cape Town and wanted to build a rondavel back home in Whittlesea. I started liaising with a guy called Neville Schenk from Built It in Whittlesea. On the quote I had specifically asked that they provide us with 6 tons of riversand (rougher than building sand). When I received the quote with building sand for R5000 I took for granted that he is referring to the river sand I ordered. I then accepted the quote and paid the amount of R66286.20 on the 21st of June. The truck arrived yesterday to deliver the sand only to find out today when the builder arrived that this is building sand and not the river sand we ordered. I spoke to Neville and told him that their supplier delivered wrong sand, we went back and forth with him and their supplier with them explaining that the sand they delivered can be used to build but then we told them we specifically asked for the river sand because the builder requested river sand and not the sand delivered. Neville then said he has gotten river sand so he will organize for delivery. After a while he called me back again saying that all trucks are out and that they will only be able to deliver tomorrow. I informed him that we can't accept that as the builders are already there coming far from Gcofimvaba so they can't waste a day and do nothing as I also took leave to come and build the house. I asked for a refund and he said he will organize it. After a while he called me back telling me that his 'big boss' says that since we did not send back the sand before they offloaded it we have to organize a truck ourselves to get it back to them and then get our refund. How am I at fault when something I did not order was delivered to my house and unfortunately did not know that it was wrong as the builders were not here with me? I am infuriated and so sad that I chose this branch only to be sent back and forth and made to take a blame over a wrong delivery that was made by your store even though I had specifically specified what type of sand we needed to build the house.