All buttons are blocked?

I have a Tricity Sovereign Electronic oven and I can't use it - the hob is still working though, but I can't cook properly without the oven!
Have tried all the possible combinations of the bottom buttons, but no result! Two of them are stuck on "auto" and until yesterday the oven worked ok and I had no problems whatsoever.Now...it's useless and I can't afford to buy a new one yet.
Need your help, please!