Entering our house after being out for most of the day, found our BT landline handset display window was lit up to show it was 'in use'. When I checked the screen, it said 'Leaving a message', but there was no message on our BT message base. I turned the handset off and on again, and it said the phone had been 'in use' for more than 3 hours, from around noon to after 3 pm. The number display showed: 01202249411. I have no idea what has been going on, or whether someone has linked my phone to a premium number somewhere! Help!