a new contract that wont be repaired under warrant

I upgraded my contract in October which is 6months ago to a s6 edge phone, after two months i had a camera defect; MNT REFUSE TO GIVE ME A NEW PHONE because of a small tiny mark.<br> Now after 6months the phone wont charge and eventually wont switch on, back to repair. After assessment they say that THEY CANNOT REPAIR MY PHONE UNDER WARRANTY because of A DOT CRACK i made on the screen ...just note please that i did scratch my screen a while ago and the phone was working perfect but since i have the phone i had noticed that battery doesnt last, i thought is because i use it a lot, but it kept on being weaker and weaker, but you know when it is a new phone you dont straight conclude that it is a defect until it just wouldnt go back on after it went flat.....<br> MTN SUGGEST THAT BECAUSE MY SCREEN IS CRACKED A LITTLE, THAT IS THE REASON WHY THE PHONE WONT CHARGE....IS THAT POSSIBLE????REALLYOH BUT THAT IS NOT IT IM CHARGED R3140 FOR THE REPAIR.....AND YET THAT IS STILL NOT ALL....THEY DONT HAVE SPARES IN STOCK!!!!! FOR ALMOST 3 WEEKS IM WITHOUT A PHONE BECAUSE THEY DO NOT HAVE SPARES AND I CANT GET MY PHONE BACK UNLESS I PAID THEM R350....I MEAN I MUST PAY R350 BECAUSE THEY DONT HAVE SPARE