This appears to be a repeat question.
PROFESSOR OF IMMIGRATION LAW for over 10 years -- This blog posting is offered for informational purposes only. It does not constitute an attorney-client relationship. Also, keep in mind that this is an INTERNET BLOG. You should not rely on anything you read here to make decisions which impact on your life. Meet with an attorney, via Skype, or in person, to obtain competent personal and professional guidance.
If you are/were admitted as a refugee, left the USA on a Refugee Travel Document before getting residency, remained out of the USA for almost four years, and want to return to the USA, you have a whole heap of issues and are not going to get the answers you need on a forum such as this. Even if you were granted residency prior to departing, you still have serious issues. You are in desperate need of real legal advice from an experienced immigration attorney (preferable one that specializes in refugee/asylee issues).
It sounds like you have a host of issues here that require the help of an experienced immigration attorney. You may have lost your green card due to remaining outside the US too long.
www.gassonlaw.com - Disclaimer: This a general answer to your legal question. Unless you have a signed engagement letter with me, you should not consider this information to be legal advice.