Product: Vehicle loan or lease

This complaint is in regards to an auto loan through VyStar Credit Union for a used XXXX XXXX XXXX. The loan began XX/XX/XXXX and is under my mothers name. I started making payments towards the loan with my checking account, within the same bank, since midXXXX. The initial payments were {$550.00}, but got higher in interest from nonpayments in XXXX. Knowing a few months had been skipped from time to time, I knew some sort of late fee would be applied or the interest rate would be higher, so I made sure approximately how much I owed each month to better get back on track. I was later notified the monthly payment raised to roughly {$640.00}, so I started making payments of {$650.00} beginning XX/XX/XXXX. A few months had been skipped again because money was really tight on top of rent and non-employment, but we got back on track XX/XX/XXXX. Making payments of {$700.00} up until XXXX, with the payment of {$640.00} as shown, then resumed XX/XX/XXXX of {$700.00}, XXXX of {$650.00}, and XXXX of {$600.00}. Attached are brief images of payments in XX/XX/XXXX and XXXX to XXXX of XXXX. I am willing to provide more information if needed. It wasnt until XXXX of XXXX when we were trying to get a loan for a trade-in car that I was aware of the remaining balance of approximately {$20000.00}. Having built my credit since then, we went back to get an update on the balance to see if we could get a car now and for some odd reason the balance is still at approximately {$19000.00}. I was unable to find documentation of XXXX payment. Even so, with the payments I had been making beginning of this year, the loan shouldve lowered to around {$18000.00}. We addressed the bank at a local branch XX/XX/XXXX and XX/XX/XXXX and even with the first print-out they provided us from XX/XX/XXXX to XX/XX/XXXX, they attempted to say the total amount shown was the principal payment and the rest had gone to interest. However, the principal amount, interest amount, total amount, and any interest adjustment is already shown in the print-out. So they tried to come up with other excuses of late fees or extra interest occurred. I proceeded to argue no late fee is over {$50.00} each month and interest adjustments are applied as shown. Especially with proof of the payment amounts Ive been making compared to the total amounts in both print-outs, theres money missing and no one can explain where it went and kept insisting it went towards some interest that they have no evidence of. The due date of these loan payments occur on the XXXX of each month, but we make payments within the first week of each month to get it out of the way. Even with any interest charge from late payments, the interest is already applied within the payment and fluctuates each month as shown in the provided documents. Late fees are also shown for {$15.00} for 3 months on record in the span of 6 months and thats only {$45.00} in late fees. Not even close to the hundreds of dollars missing. Attached proof of payments are also labeled under different descriptions each month instead of transfer to loan XXXX is also suspicious. Although we only have evidence of missing money from payment amounts for 6 months back, who knows how long this has been going on for and we want our money back.