Bad Service and Communication

On Monday 11 June I phoned this dealership to arrange for the audio system of my car to be sorted out. The lady i spoke to took my explanation of the problem I had with the system, my details and said the service was booked. So I took in the car this morning , 13 June and I was shocked by the way my issue was treated. I got there and an Indian guy called another guy (who looked like the technician) to look at the audio system and they then said it should be removed and will be put back again. That will be at a cost of R856.00. At this point I mention that the car is still under warranty and I should not be charged. He continued to say that even then, it is chargeable. So, I decide to leave because this cost was not in my budget and had the lady i spoke to on Monday mention this, then I would have made a conscious decision to take it in or not. My anger is not that they want to charge me, its because they failed to communicate this to me initially when I contacted them. Which means I wasted my morning having to go there just to be . Ford Bruma, please MAKE SURE WE ARE INFORMED OF THE CHARGES BEFORE HAND.