Check pricing, recheck and check again.

I made use of this company to clean my solar panels. Received a quote for R 8,142 to clean all my solar panels twice a year (at my office (12 panels) and private residence (20 panels)). After receiving the quote I indicated that I only require my private residence to be cleaned. After cleaning I received an invoice for R 3,464.66 (which should have cost R 2,544.37 as per the original quote) for just my private residence. I indicated to the owner that something does not seem in order as this is similar to what was quoted for my office and private residence per service. He indicated he will recheck the pricing. Two days later I still received the same invoice (with a bit of discount) for just the one site and a new quote to clean both sites twice a year for R 10,367.25 just to get told by the owners wife that "sorry she made an error on the original quote" and that was that.