Voda****.. do not purchase anything ever!!

I took a upgrade last year ,a Iphone 8 plus in rosegold which is now a few months old. In my pocket my keys put a small mark on the top of the phone barely noticeable. Now the phone just stopped working - iv taken it into vodacom for a checkup... they wanna quote me nearly R9000 for a replacement. I understand the warranty is now void ?! its obviously a manufacturers fault due to the fact that they wanna replace the phone and the small mark has nothing to do with this issue - the phone has never fallen. Im only a few months into the contract at R850 a month and now they wanna **** me over like this. I contacted the repair centre and a very rude woman kept repeating saying that the phone must be replaced but wouldnt tell me what the problem with the phone is - saying that the small mark cannot be overlooked. Im gutted .. this is the last time i buy anything from vodacom. Poor customer service and really poor ****ing conditions which i think are there to rob people and get out of warranty