No part available for glass top hob

According to Hirsch repair centre Durban AEG do not have a part to replace a faulty electronic switch to switch between half plate and full plate on the main cooking plate because this is an old model, I buy (bought) AEG appliances because they are high quality, reliable and had great service back up. The hob is not more than 10 years old and is otherwise in great condition. I must now replace it because I can't cook with anything except a small pot. This electronic switch cannot be so unique to this model that there is no replacement, or is Hirsch spinning me a story? very disappointing!