Cell C Bad service

I gave phone in for repairs as it did not connect to sim, 21 March - last week only got hold of someone to assist me, just to tell me i need to pay R6250 as i damaged the phone, which i did not, after requesting photos i found out it was damaged by repair department, now no on can tell me what are they going to do about it, replace phone or repair, phone still om contract and i am still paying for it , don' t have a phone to use, as they could not lend me phone either, i will never use Cell C again, worse service ever