Product: Student loan

I have private loans for school through Navient. 
- Fee 's were assessed when I was in school. 
- Most Fee 's were reversed after proof sent to Navient showing I was in school status. 
- {$27.00} in fee 's remained after very lengthy back and forth. 
- Several month 's later I received a bill for {$27.00}. Called Navient, spoke to female CS rep who advised me to pay the fee online so I could avoid large fee to pay by phone. 
-Paid {$27.00} online per first female CS rep direction on XXXX XXXX. Payment posted to account undefined on XXXX XXXX. 
-Received second bill in XXXX stating I owed {$27.00} due by XXXX XXXX. 
- Spoke to second CS rep ( male ) who stated that 'no matter what I do, I have to pay the interest on the loan first, then the principle, before any payments apply to the late fee. 2nd rep advised a refund was not available. 2nd rep informed me that I should not even be billed due to in school deferment. 2nd rep stated that since 1st rep misinformed me, he got approval from his supervisor to have the remaining {$27.00} fee removed. Advised by 2nd rep that it would take a few days for fee to be removed. 
- After 1 week, fee was not removed. Called and spoke to Rep 3 ( male ). Rep 3 says Rep 2 messed up in sending information to have fee removed. Rep 2 got a second approval from his manager to re-send the request to have fee removed, due to all stated above. Rep 3 advised me that the fee would be removed by no later than the next day. 
- After 2 days, fee was not removed. Called and spoke to Rep 4 ( female ). 4th rep claims that both approvals were denied due to earlier reversal of fees on the account. ( The fee 's that should have never been assessed due to being in an in school status as explained at the beginning of this explanation. ) I explained that the fee 's should have never been assessed due to being in school status. Rep 4 mentioned a refund, which Previously I was told was impossible. I asked to speak to a supervisor. After a lengthy hold, rep 4 came back on the line and said that Navient was going to do a " special approval '' for this fee to be removed by the following day. She asked if I still wanted to speak to a supervisor. I said yes. 
- Supervisor XXXX came on the phone. He stated that any payments sent to Navient are automatically applied to interest first, then principle, then fee 's. He stated I should not be billed due to in school deferment. He stated the fee will not affect my credit. I explained to XXXX that the fee 's should never have been assessed due to my in school deferment. I stated that I have been receiving bills for this fee with a due date of XXXX XXXX. I stated that the first rep misinformed me regarding making the payment towards the fee. I stated that I did make the payment for the fee which is reflected on XXXX XXXX in the amount of {$27.00}. XXXX claims that what i received was not a bill. ( see uploaded proof of bill ). I told him no, it is a bill, it states a due date, amount and had a return envelope. I explained that anyone who received this would have paid it thinking it was a bill, only to discover that it would not be applied to the proper area. I explained that is a bait and switch tactic and was illegal. I explained i should not be billed, and i was billed. I explained that if this is not fixed within XXXX hours that I will file a complaint with the CFPB. XXXX stated he understood and that it will be completely rectified by XXXX/XXXX/2015. 
- Went online to check if fee was removed. Fee was NOT removed. 

-Also note I sent several emails via Navient website and NONE were responded to.