Default [Q] Xperia Ion, battery issue

I desperately need help with my xperia ion. The battery seems to be broken. When I charge the phone, the red light lights up. A few seconds later the phone tries to turn on. The screen lights up but then shuts off again even before the xperia logo appears. It keeps doing that every few seconds. I tried the volume up/down and holding the power key. The phone vibrates once and then a blue led screen lights up and nothing happens.
I already ordered a new phone but I desperately need to recover one of the messages I received. Sony companion doesn't see the phone so I don't know what else to do.
Please help!