Navient Solutions, Inc. Student Loan Complaint

Navient Solutions, Inc. Student loan department,

Non-federal student loan Dealing with my lender or servicer Trouble with how payments are handled California

I received a settlement letter in - 2015 for $2200.00. I have made all the payments and Navient sent my account to a collection agency for the full balance even though I made all settlement payments. I paid off the settlement early and have attached copies of the money order receipts. The last I heard from Navient was on - -, when they told me that my payment had been applied to a different account, that they had fixed it, and that I would be receiving a settlement in full letter shortly. Instead, I received a collection letter for - - for the full balance with no mention of my settlement or the settlement payments I made.