I have exactly the same problems with my Experia M, which I got from O2 on monthly contract late January 2014. I just thought it was heavy on the battery and wished I'd never got the phone. However last week, like you, turned on phone after a night on charge and it stuck on Spny Experia opening screen and would do n othing more, could not turn it off or on, and the phone was hot to touch. Took phone back to O2 shop who said they would send it away for repair. I have just got phone back after being told it is 'Beyond Economical Repair' and problem is not covered by warranty. I a, now left paying a contract for a phone I no longer have. O2 state there is nothing they will not supply me with a replacement phone as the problem has been caused by 'Customer'!!! Considering the phone is only a matter of months old and had very little use (cos I dont like it) and having read here I think its about time Sony stood up and accepted there is a problem with many of the phones and shouldbe replacing or recalling them. oh asked what the problem was with my phone that was not covered by warranty and told charging port was damamged and it must have been by customer!!!! Not true at all, it has always been a hot phone from day one and I do know how to plug and connect phone Sony/O2.
