work permit for over 60 years of age

I worked in Tianjin and Nanning for 3 yrs. I am married to a Chinese citizen and will be returning to China. I have been offered many jobs in China but because of my age, I don't qualify for a Z visa. I have been told to apply for a class B work permit and I have all the papers needed but I am not sure how to get it or who I should contact in getting a class B work permit. I am on WeChat under diyguy1, hope you can help me. I had a Z visa and I did have a residence permit.
Alby