Product: Vehicle loan or lease

Car purchased in XX/XX/XXXX. Extra amount paid to account every month, through my bank bill pay option, with a phone call every 1-3 months to have the extra applied to principal. During each call, I would also ask about paper statements as they were inconsistent, eventually becoming non-existent in the mail. 
Late XXXX, I again asked about putting extra in account towards principal. I had just had a payment clear my bank account and had mentioned this to gentleman on phone. Receiving confirmation that in 1-2 days it would be applied to principal, I also asked about statements. I was told it was also taken care of and was assured statement would be received for the next month. 
The following weekend, the XXXX app told me there was a balance due on the account, but due to timing of alert and call center hours, I had to wait until Monday to learn that the payment and excess on account had been applied to principal. This resulted in appearance of no payment, penalties. What followed is several weeks of phone calls and continued assurance that this would be corrected. Instead, I received notice three weeks later that a ding was going to hit my credit due to late/missing payment. It took three MORE phone calls to finally find someone willing to help me and personally take responsibility, calling me back regarding correction to the account.

After two years of requesting paper statements or digital ones, I finally spoke to someone able to correct the digital statement setting to allow my account to collect statements so that I can track how much is being applied to the principal on account each month. I am missing consistent statement history. For a loan that is 2.5 years old, I have 9 total statements available for my review. Digital or print. I have never received requested transaction report after the XXXX snafu. 
This past month XXXX XX/XX/XXXX XXXX, I requested TWICE, via the app chat, to have excess on account applied to principal. Each time assured that it would be taken care of within 72 hours. This afternoon, I called asking for extra payments sent to be applied to principal. In reply to question about balance on account, I learned that the excess in account prior to XXXX payment was never made to the account. 
After every request for principal payment, I am instructed to wait up to 72 hours to see changes made to account. However, there is no balance available on my account, just what is due each month. With inconsistent statements, this has become a daily task to verify payments have been made correctly to account. 
This has been a monthly headache for the life of this loan and is quickly becoming a UDAAP issue due to payments not posting to my account in a proper and timely manner, the inability for me to balance my own account due to limitations of statements and detail within app, no statements available to review, and falsely threatening to report credit status to bureaus. Having a car loan should not cost me 30+ minutes of every month making sure my account is as desired. Nor should it take more than ONE contact to ensure that statements are sent to me or that payments are made correctly to the principal of my loan.