Am not happy at all and again they overcharged me

Hi, Friday 13 September I visited edenvale branch to book for diagnose service and when I do a quotation they told me that to diagnose is R1100 ,then i was happy with that. I booked my bakkie for Monday 16 September, then around 14h00 I called the dealer regarding the findings on my bakkie, guess what: a lady called Rose she said to me she was about to phone me , then she told me about the problem and the quote to repair, when I said no is too much I will pay only diagnose she said come . When I arived they charged me R3381, they overcharged me and she is very Rude when i tried to ask why they increase the money.