Phone self cracking. Warranty refused to repair.

On the 4th of December upon waking i find my phone,a Sony Xperia z2 on my dresser.<br> The front screen was completely shattered although no glass was missing. and the back had a small shatter around the middle area.<br> <br> Upon contacting sony mobile with regards to the issue via their website i was presented with a reference number by the automated system and months after there has been no response. i contacted sony mobile south africa by the facebook page and according to them its wear and tear, the phone was 6months old purchased in june.<br> I sent it to warranty assessment with vodacom and warranty repair was refused and i was quoted R3100 to repair.<br> I refused the repair. and tried seeking help and i was sadly unable to. this current week I decided to send my phone in to be repaired and agreed the fee. but what i found, quite conveniently was the lady sitting next to me with an xperia z1 smartphone had a similar issue with hers cracking only on the front screen. I previously posted a complaint here someone from sony asked for my contact details. I was never contacted.<br> <br> I am worried this incident with my phone screen shattering will occur again once repaired and i'll have to pay