Phone shows red power bar and 6% charge. Plug it in and IMMEDIATELY it shows 43% charge. I assume the battery is gubbed 
Still, I have got a warranty 
But then I have to get the monkeys in the shop to transfer everything to a new phone

Your phone should come with a suite of software for your PC.
install the software
Connect your phone to the computer
Backup all your information
Connect new phone to computer
Restore information.
Simples
