Product: Student loan

First of all please note I have never in my life filed a formal complaint against anyone or any company. 

We have had a total of 7 student loans with Sallie Mae/Navient beginning in XX/XX/XXXX. We have consolidated or paid off all but 1 loan ( XXXX XXXX XXXX ) which has a current balance of over {$43000.00}. We have always made the payments not really monitoring the principle balances. Our most current Statement Dated XXXX XXXX shows the current amount due is {$300.00} and the Current Amount Due date as XXXX XXXX which is 4 months from now. We have from time to time skipped a single payment all together, thinking we were ok because like with this current statement the payment was not due for a month or more. We recently had cause to look back over the XXXX XXXX XXXX loan and realized there were 30 months when the payment went entirely to interest with {$0.00} going to the principle. This loan has had no late fees ever charged. The first time I called Navient many weeks ago about this I was told We had missed or been late on many payments and we were concerned that they couldn't find the confirmation numbers that their system had given us for online payments. However we have never missed a due by date, we frequently pay more than the minimum, and there were never any late fees charged so I don't understand how they can say payments were late. ( There is an XXXX document attached below. ) During the second phone call the representative we were talking to commented it seemed to be a problem that the due dates were being extended. He did explain the interest was accrued daily and how I can see the current interest balance due on the website. I still don't understand how a payment due date is extended into the future without it being a full payment including interest. The interest is accrued daily but isn't factored into a payment that is advanced? So when we occasionally skipped a payment or just delayed a payment because the due date was a month or more in the future the interest was actually piling up and the full payment and extra we thought was going to the principle was actually all going to interest for a total of 2 1/2 years over the life of the loan to date. Furthermore, the frozen principle balances started months before the skipped payment they attributed the problem to in the course of the phone call. We had believed we were dealing with a reputable company. I have to wonder how many other accounts with Navient are experiencing the same misrepresentation. It is completely misleading to the consumer to say a payment is not due until months from now and then allow the interest to continue pilling up and then everything paid is being consumed by the interest balance. That is setting the consumer up with misinformation. IF THE PAYMENT DATE IS BEING ADVANCED IT SHOULD INCLUDE THE INTEREST FOR THAT PERIOD. How does Navient determine how far to advance a payment due date? The original loan consolidation in XXXX was for {$50000.00}. Since then we have paid only {$6900.00} in principle and {$26000.00} in interest on this loan. I now have a better understanding of how this is being manipulated and will definitely be dealing with this differently going forward. There is an awful lot of very small print on the back of the paper statements. The consumer is definitely at risk dealing with this company. We had to go to a different repayment scale a couple of years ago which obviously reduced our principle payment each month. However we have made many payments larger than the required amount due, including during the time that the principle balance was frozen and they put the entire payments to interest. If we hadnt realized what was happening we never would have gotten this paid off. 30 months of payments in the past 7 years have already been all interest even though many of them were for more than the amount due. If we're a month ahead on a car payment or house payment and then have to skip a payment it's no problem. The interest is already part of the payment. Not true with Navient. They say your next payment due is 4 months from now and quietly pile the daily interest onto the loan and all of your future payments go to the interest until that interest is paid off.