Gross overcharge for satellite dish and services

I had no signal on TV, and a technician from Digitech Projects came in. He replaced my satellite dish which he claimed is Fibre, which it is not, for R4450. The LNB receiver charge was R1800, when they are actually in the region of R500. The call out fee and labour charges was R2200. I paid R8250,75 by instant EFT. I have subsequently sent him a message, disputing the charges and the claim that the dish is a fibre one. I have tried to phone several times, but my calls are not answered. The invoice was unprofessional with misspellings. I suspect that this business is a rip-off. I want to warn anyone not to go near them.