Help cracked edge screen

I've had my s6 edge since launch and have had a Samsung case with it since then, few weeks ago I noticed a hairline crack along the edge part of the glass running down for a couple of centimetres, the screen itself is fine. Haven't dropped the phone, haven't bashed it against anything, doesn't stay in the same pocket as my wallet or keys Now im so religiously careful with my phone I cant for life of me figure out how this has happened..
Turned to the old trusted source of Google and seen a lot of similar tales of mysterious cracks relating to overheating/battery etc. So I took the phone to a Samsung repair shop and they stated that although it doesn't appear to of been dropped or pressure applied to the screen they couldn't say for sure why its cracked and wanted £189 to fix it, I complained to Samsung Customer Services and they stated basically tough luck the screen isn't covered by warranty & that they've have been through rigorous testing so this wouldn't happen.

I have insurance but don't see why I should have to go through that or pay £189 for something that isn't my fault.

Any advice?


Thread starter
UPDATE if anyone is interested, after back and forth between Samsung & Three, Samsung pretty much are not acknowledging there maybe a issue and the s6 edge is oh so perfect, turning to the good old sale of goods act so three (as the supplier) eventually realised due to my persistence they had to do something, so to determine if its defective they have decided on a fix it and see solution so Three are paying for the screen to be replaced by Samsung and Samsung are going to replace the battery and any other components that upon inspection warrant replacing. Its been a long fight but got there in the end.