Samsung — shattered screen

dear sir. this is the third time i have submitted a complaint. no feed back as yet.
on 30th of august 2013 i signed for a 18 month contract with o2,
with this contract i recieved a galaxy samsung fame mobile.
over the weekend i noticed a small crack on answering a call tapping the phone the screen shattered.
this phone had not been dropped, knocked, and mistreated in any way . i have never had a problem with my mobile before.
o2 sent it to there workshop for repair but would not do it under the warranty. the phone is only six weeks old.
they said i would have to pay £73 .
i feel this is very bad service, they advised i contact samsung. i only hope you can help me on this issue .
i cannot afford to pay £73, i rely on my mobile due to severe back problem.
kind regards
elaine perkins
mobile [protected]