who is this company?
Anyone has website address or phone # i can contact for rehabilitation?
thank you in advance.

US Dept of Ed of the United States Department of Education.

This sounds like you are reading something off your credit reports. If so, then a direct contact address and phone number should also be on there. That would be the best way to know that you are contacting the correct department for rehabilitation.

FISL means Federal Insured Student Loan. Are you sure it's SF and not FS? FS I think is Federal Stafford. Never heard of SF. At any rate, it's the US DOE that you're trying to contact. If you don't have a number on your credit report, their main web site is www.ed.gov.