Where can i get my bosch microwave oven rep...

Our Bosche microwave has failed to work, it was bought 5 12 06 and failed, it was repaired on 20 12 06 , bottom hinge faulty,eng no 70792. It has the same symptoms, some days it would work after several attempts, butnow it will not work at all. Can you give me any hints as to how I might get it to work? Is it out of guaranttee? How much would it cost to repair it, the last time was 36 mins? It seems to me to be a faulty model to start with and at the price we paid, three times what an average one cost a poor deal.