Vent about banks

I just need to vent about our bank. Actually it's about all banks. I actually really like our bank. It's a small town bank and everyone knows everyone there. But yesterday I got very frustrated with them. We have our car loan through them and we've decided to make some extra payments. I put Nathan in charge of it and he said he could do it online. I told him to make sure it went to principle because when I worked at a different bank, if someone didn't come in and specifically tell us to put it towards principle, it automatically went towards interest. (I thought it was a stupid thing for a bank to do, so I would always put extra payments towards principle. I can say that and they can't do anything because I don't work there anymore.) He made the payment and later that day I went in to look at our balances at the bank. THE PAYMENT HAD GONE TOWARDS INTEREST!!! I called Nathan, but he was on top of it. He had gone directly to the bank the second he made the payment and had seen where it went. Here's my vent. Who in their right mind would make an extra INTEREST payment?!?!?!? Why would a bank even set it up that way? Okay, I know WHY a bank would set it up that way, but it's completely dishonest and crooked. Like someone is going to come in and say, "Here, I've decided that I'm not paying enough interest on this loan. Can I take this $100 and just put it towards the interest." Anyway, that's my vent for today. If you ever make an extra payment on a loan, MAKE SURE IT GOES TO THE RIGHT PLACE!! Thanks for reading.