Teka HA830 ?

Hi there !
We had a power cut in the night and cannot use the oven until we set the clock, however, the buttons on the clock had stopped working long ago and pressing them ( in any order or combination) has no effect at all. Does anybody know if there is some way of over-riding this, as it seems ridiculous that we are unable to use the oven or grill just because the buttons on the clock are not working !! Surely our oven (less than 2 years old) is not destined for the scrap heap because of this ?!