Appalling customer service!!

I went around searching for quotations online and places I could drive to in order to get materials for the slab as we are building a double storey. So 15 June 2021 I found a place called Rhino Slabs online and sent an enquiry together with the plan I had on my phone. Then I got a response about 30 minutes later and I thought great, all went smoothly and the quotation was sent which was cheaper than what was given to us by a previous supplier. Anyway fast forward, the engineer came through to do the proper measurements of the building and all the materials that will be required. Deposit was paid 16 June 2021 and I sent Clinton Koekemoer (Sales Consultant) the proof of payment in email. We were told they short staffed as about 10 staff had covid and the delivery will be delayed, who's problem was that but anyway we practiced patience. The engineers design came through 23 June 2021, and we were happy... Or so we thought, 27 June 2021 final payment was made before delivery a small portion of the blocks was delivered and no one left a delivery note or bothered to knock on the gate as there was someone at home when they brought the less than expected blocks for the slab, the ribs also were the incorrect sizes, Clinton Koekemoer stated that the other materials will still be coming they still short staffed and their trucks need sanitizing before leaving the depot, yet again I kept quiet and patiently waited. Last week Thursday 2 July 2021 other materials were brought and yet again the incorrect blocks, I told Clinton that these blocks are incorrect and can they do the exchange for the bigger blocks, Clinton stated that we should await all materials to arrive before we decide to send back the incorrect materials, in which we did. Since yesterday 6 July 2021 his giving us the run around going back and forth and all we asked him to do is come and take the incorrect bricks and swap them out for the bigger slab bricks and yet his refusing, his ignoring us and treating us as if we never paid!!! Then he turned around and said that he will send the guys to do the swap out today 7 July 2021 provided we pay the delivery fee, which we didn't even have an issue but since his playing nasty then I have no choice but to escalate this matter because clearly he feels we have no voice as we being nice and he (Clinton) thinks he can take us for fools. I want the manager or higher authority to contact me and resolve this asap as we need this project completed before Friday 9 July 2021... Clinton lacks communication skills, I really wonder how he got the job there as he don't know how to communicate, I keel telling him countless times to phone before the guys make a delivery and he always fails to do so, or is Clinton's aim to deliver the materials without calling as he feels no one will be home to collect a delivery note or count what supposed to be there??? Who is fooling who here??