I get a pension from having been a Federal Employee; I also work part-time for my family's business. Do I need to pay into EI?

Question

So, I worked for the Federal government most of my life, I retired 2 years ago and I get my pension. In addition, I work about 30 hrs/week in the office of my family's business, do I have to pay EI? If not, Can I get a refund for EI payed during the last 2 years?