NO WARRANTY ON DESIGN FLAW

My Sony Xperia Z1 Compact, screen cracked while entering my password pattern, phone was not dropped or misused in anyway. I HAVE CALLED SONY AND THE SAY CRACKED SCREENS ARE NOT COVERED BY WARRANTY WHICH IS ******* ESPECIALLY IF IT CRACKS ON ITS OWN IN YOUR HAND!! I am not willing to pay to get it fixed and either want it replaced or repaired AND IS STILL UNDER WARRANTY, as it was of no fault of my own and is a common problem with the Sony Z1 range as iv researched A SIMPLE GOOGLE SEARCH WILL SHOW YOU HUNDREDS OF CASES! I am extremely unhappy with the service.