car radio problems.........please help

Help........

I have a 2007 skoda octavia fsi estate for nearly a year. Just recently the radio comes up with PHONE across the display and then none of the buttons work, so i cannot even turn it off and it just drains the battery, so have taken it out from the car.

I have taken these measures to try and fix it but nothing seems to work so just before i go out and sort out a new radio i wondered if anyone could help.

So far i have checked

1. checked the bluetooth settings and found bluetooth is not connected to the radio, done a search for bluetooth and no rogue devices unknowingly left in the car switched on.

2. had an electrician totally strip the radio out and check for lose connections and possible short curcuiting and that came back as totally clear and nothing wrong with the radio.