A4 Phone Connection

Hi,

My 2005 2.0T Avant has the Bluetooth phone connection selected via the Mode control on the steering wheel. All okay until yesterday when the phone went flat & turned off during a call now the system has stuck in "Phone " mode with the word "Phone" permanently on the radio display and the number I was talking to permanently displayed on the DIS. Try as I might I can't clear it and am missing the radio!
Any ideas? should I disconnect the battery? I have tried removing a few fuses but without success, can you reset it in some way?
Guess I can talk to the dealer.......

Thanks for the feedback, I did try this along with two fuses that are labelled "Telephone" neither Telephone fuses switched off the DIS so not sure what they do. The Radio fuse did switch the radio off but did not clear the fault. Booked the car in at the dealers and then the fault cleared itself!! obviously the car didn't want to go to the dealers any more than me.