Product: Student loan

I pay $ XXXX monthly to Navient. Very frequently over the past XXXX years they add a late fee bringing my payment to about {$1800.00}, but the payment was not late. It was paid within the grace period between the XXXX and XX/XX/XXXX of any month. When I ask why is there a late fee since I made the payment within the grace period they say there were late fees assessed going back years. Another tactic they use is telling me the payment including the late fee, the portion that would normally pay the late fee is directed at the old balance and the late fee is not paid but carried over again. I have on numerous occasions over the years asking. TODAY, what is my balance in late fees and when I py that amount, they once again apply it to the balance and not the late fee. On XX/XX/2016, within the grace period, I asked them specifically to apply a separate payment to all outstanding fees and was told the amount is {$250.00} which I paid and thought all late fees were paid through XX/XX/XXXX. In XX/XX/XXXX the correct amount was charged, {$1700.00} due XX/XX/XXXX and I paid that even earlier in on XX/XX/XXXX. The next payment due for XX/XX/XXXX once again includes a late fee and the amount due in XX/XX/XXXX is {$1800.00}, an extra {$150.00}. When I asked why is it more, they said I had unpaid late fees. This practice is outrageous and borders on extortion whereby Navient is charging hundreds of dollars in late fees with hundreds of thousands and perhaps XXXX of customers and getting away with it as a late fee charge, then when paid what they say includes a late fee, only to find it was applied to the balance. Now I have another complaint : Whenever I call Navient or even the direct line to Sallie Mae in XXXX, PA, it is all ways routed to the XXXX. ALL WAYS. XXXX I ask to speak with someone in the XXXX, they tell me there is no one available in the XXXX, ever. All calls go to the XXXX. This is also outrageous and they are getting away with breaking the law. Finally, as I put XXXX kids through XXXX, XXXX and XXXX XXXX and a loan in the area of about {$150000.00}, MY XXXX PAYMENT, ON LINE AND IN MAIL WAS ALL WAYS FOR XXXX payment. However, all most 6 years ago when I missed some payments, XXXX XXXX reports to the credit reporting agencies, not XXXX payment was missed, but XXXX payments were missed. For the past 6 years the credit reporting agencies have been reporting me as someone that has missed XXXX payments for the past 6 years. Any creditor who sees this will immediately have a much more negative opinion of my credit worthiness compared to some one who has missed only XXXX payment. Please explain how this is fair to me or anyone else. For XXXX and XXXX years I have been paying monthly around {$1700.00} x 66 months = {$110000.00} and the credit reporting agencies tell the world and any creditors I am NOT credit worthy while they make XXXX % off my loan. 
Is n't XXXX great!! They have never chased me for money, make outrageous interest on educational loans and tell everyone my credit sucks. There sould be a class action law suit filed against these loan sharks. No wonder no young person in the XXXX can repay any educational loan. After telling the world I am not credit worthy for XXXX years, by nagic my credit score will jump dramatically because I pay XXXX mortgages, many loans and approach {$25000.00} monthly in payments but XXXX XXXX and Navient say I am not credit worthy. Do you think if I call the XXXX Police they will help me with these thieves????