if I have a case against Navient

I would like to know if I have a case against Navient. Yes Three years ago Nelnet forgave all my Student Loans under the Teach program. In January I started getting Bills from Navient for about 5 loans. Now understand I havenot heard from them in three years. I called Navient and they said that they had refused my application because it was undecipherable. I told them that in fact they were approved for forgiveness three years ago. They told me to call nelnet. Nelnet agreed with me. They told me to contact navient and the carousel ride began back and forth. Both parties refuse to talk to each other claiming I must settle it.. They have ruined my credit and I am tired of it..