Sallie Mae Student Loan Complaint

Sallie Mae Student loan department,

Non-federal student loan Dealing with my lender or servicer Keep getting calls about my loan New Jersey

I had to co-sign for my son 's Sallie Mae loan for his senior year of college. According to my MSA, ( Marital settlement agreement ), my ex husband is responsible for - of ALL college expenses, and student loans were NOT to be in the children 's names. I also have a court order ( - -, 2016 ) in which orders the loans to be transferred into HIS name. I have spoken to Sallie Mae, and they refuse to transfer ownership of the loan. Please advise how to proceed