Yes I have one at the time of leaving company. Is that old one is ok or i need a new one? Besides I have all relevant document.
If you got that letter the moment you left or after, it's valid forever.
So, if you tried every single thing to get the reference letter, try adding as much as possible from the following:
-Communication (emails, texts, etc...) with HR or supervisor clearly showing their refusal
-Your entire work contract
-A notarized affidavit from you stating duties and all other missing information
-Your employment letter you got at the time of leaving the company
-Some payslips, like the first three and the last three
-If possible, some examples or visuals of works you have done related to your claimed duties
-Any, any, any document you personally feel can support your application.
To be honest, it will always be at the discretion of visa officer to accept or not your alternate documents, but do your very best! Anything to show good faith and honest efforts!
To answer your question about CIC verifying work experience, I have never personally heard of anyone having their employer or ex-employer being called up to verify, unless they have a serious doubt about the legitimacy of documents or claimed information. Some countries are flagged as having many cases of misrepresentation, and may therefore be more careful. But officially of course, they reserve themselves the right to employ various methods of verification like calling the person who signed the letter to see if he/she remembers signing anything at all, calling HR to see if they have/had the applicant in their records, or in some extreme cases doing a on-site visit.
