Nelnet Student Loan Complaint

Nelnet Student loan department,

Non-federal student loan Dealing with my lender or servicer Don't agree with fees charged Maine

In 2006 I cosigned a private student variable rate loan. The interest rate at the time was 8.68 percent. Today the rate is 8.75 percent .Even though the prime rate has gone down substantially the last 10 years the rate on the loan has not been reduced. It seems that the rate should have dropped. I have called the company and they have not given me a satisfactory answer. I think there is fraud here. Please advise