mobile

" Sameer: Sorry to inform you that as the device will be sent back with out any repair as it was rooted."

Unbelievable.
The phone had been playing up for 2 weeks, shutting down between 70-40% battery for no good reason. I flashed 5.1 again and factory reset it. Surely that is enough to un-root it? Or do they have some special way of telling if it's been rooted before?
At the moment it seems they are posting it back to me, so I'm down the £7 in postage to them, and I now have a faulty £500 phone.
Anyone know what I should do?

I originally rooted it with 'CF-Auto-Root-shamu-shamu-nexus6.zip' and run the 'root-windows.bat' - believe while in fastboot?
I also flashed the 5.1 update straight from the google website - also through fastboot I believe..
But I do remember when I booted it up just before packing it up, that the unlocked padlock wasn't there...

I even tried google but they won't RMA it because I didn't buy it from them.