Work experience proof question? All experts please help.
 

I am currently a student studying in Canadian university and working as teaching and research assitant as my part-time job. Before I got enrolled in the study program,I have worked in two companies. I quited the first one after a year and worked for the second one for three years. So, I submitted reference letters from my current university employer and the employer I worked for(for three years) before I took the study program as my present and previous work experience reference letter. Is it correct? Notably,I won't gain any more points by proving I have more than three year's working experince with my work category under the old regulation. Besides, it's hard for me to get a reference letter after losing contact with my first employer for almost four years.

All experts,please kindly advise.