Mtn
Minor repair on phone resulting in cracked screen

I booked my HTC 1X in at the MTN Walk in Centre in Midrand (HVRC Midrand) because it had a display issue. I was assured that the problem would be sorted out in 3 to 4 days and because it was under warranty it wouldn't be and issue.
I got a report claiming that it was out of warranty (which is incorrect) and was given my phone back with a badly cracked screen yet when i booked it in it had not physical problems other than the blank LCD.
Its been 3weeks and nothing has been done. My phone was damaged and instead of being assisted i'm being moved from pillar to post.
The phone has been rebooked but there is no solid assurance that it will be sorted out.