2 hobs on my induction cooktop are not working?

DeDietrich MODEL DTI309 induction 5 burner cooktop - hob in front right stopped working a year ago and now the left back hob is not working. When you put a pan on it it just blinks like it doesn't recognize the pan. What could be the problem?
And WHERE can I order the parts because when I call DeDietrich in the UK they say they are not permitted to send the parts to the US!!! a Safety issue??? Please help as A new unit will cost me $5000. Thank you for all your help