Quotation manipulated by the repair centre

My phone went into flight mode and never came out! Booked it with cell c for repairs as it is still under warranty? The store has proof that my phone had do dents or physical damage however a quotation worth R10 900 came back claiming that my phone had physical damage!!! There are even pictures at the store that shows my phone had no single dent!!! The consultant who assisted me can even attest to it because she is as livid as I am right now!!! CLCGPEven if it was said that my phone had a Crack on the screen, the crack wouldn't cause a phone to get stuck on flight mode!!!!!! I am livid with this kind of treatment, they are manipulatung quotations!!! I am heading to the head office some time this week!!! I am tired of you guys taking clients for a ****!!!!!!