Product: Student loan

I set up autopay well in advance of repayment going into effect. From the beginning I could not tell what was actually my minimum payment since different amounts were listed on every communication I received. I saw an amount of {$300.00} something in some places but when setting up autopay it said amount due monthly {$16.00}. To try and cover my bases I set my payment up for {$400.00} and received confirmation. In XXXX they withdrew my {$400.00} and then several days later withdrew another {$370.00} inexplicably. I sat on hold for XXXX hours just to be told that they couldn't see why that would happen and that it must be a random error but that it would take too long for them to back out the extra charge so I should dispute it with my bank. This didn't make any sense to me but I did it any way which was a tedious claim process that I had to provide documentation for. A couple days later I got an email saying my auto debit was cancelled because my payment was returned for insufficient funds. I was so annoyed because they had told me to dispute the charge. I called and sat on hold again for over XXXX hours because I wanted to make sure when setting up autopay again that everything was correct and I wouldn't be double charged again the following month. The guy seemed very confused and kept telling me different amounts were due on different days. I said I understand that but it clearly says on your site to call to have the loan due dates and amounts aligned and that even if there were different amounts, the payment I scheduled for auto debit was slightly above all those amounts combined so it should logically be covering everything and that how can I possibly make payments on different amounts when when I log in it shows my total due as {$16.00}?? He told me that made sense and after " checking with a supervisor '' assured me I was setting it up correctly and that this was just a random error. Fast forward to XXXX and my {$400.00} autopay comes out and then the next day another {$370.00} comes out. I call and sit on hold for XXXX hours and then the line just randomly disconnects without me being able to speak to anyone. I give up hope of getting the extra payment refunded and I'm not going through the process of another bank dispute. I cancel my autopay because I do not trust this company. I emailed them a complaint yesterday and receive a notification this morning that I have a message in my account. I login and am positive there will be some resolution. Nope it's a notification that they received my request to setup autopay as of XXXX which makes no sense because I removed it on XXXX or XXXX when they double charged me. So now they are just authorizing things without permission. I am going to remove all payment methods from my account and will have to manually make payments every month but I don't even trust them to process those correctly. Now my amount due on my account again shows something completely different and I have no idea what my minimum monthly payment actually is. I have had to rearrange my other bills because I did not plan to pay nearly {$800.00} when I could barely afford to pay the amount I expected to be withdrawn.