Product: Vehicle loan or lease

There are 2 issues One I called in XX/XX/XXXX and asked for a payment deferment of one month, they said they could only do a payment reduction, so I was to pay {$310.00} for XX/XX/XXXX. I paid {$320.00} then in XXXX I paid {$640.00} and after that payment I received a letter from BMO Harris Bank stating I was approved for a 3 month reduction and then in XXXX I paid {$360.00} +/- I can not remember that amount, then in XXXX their website showed I currently owed {$0.00}, and my next payment due was XX/XX/XXXX. I thought since I overpaid the reduction that is why it showed {$0.00} owed. I received a letter on XX/XX/XXXX that I owed {$510.00} in late fees. also now my account showed me past due {$290.00} something dollars on my account. I called the number listed which took me to the collection dept and I s/w someone on XX/XX/XXXX and she said all I owed was {$290.00} something so I paid {$300.00} that day. Then she transferred me to the payment dispute dept about the late fees on XX/XX/XXXX I s/w XXXX and she said that those fees are from the payment reduction plan and I should not owe those and she would take care if them. The next week I received another letter from BMO, so I called to make sure " it was taken care of '', I called on XX/XX/XXXXXXXX  s/w XXXX she said at first, she could not see where I s/w XXXX, but then after searching she found the rep I s/w and that there was a recorded call of my conversation. XXXX also said those fees were from the payment reduction plan. I said if you all approved me to have reduced payments why are you charging me fees? She agreed and said she needed to s/w a supervisor about waiving fees, she put me on hold and after speaking with a supervisor she said the person she spoke with was only authorized to waive so much and she would waive half, but XXXX felt I should not be responsible so she was going to submit a request for all to be waiver and would know in 48 hours. she said she was off Wed and would call me Thursday XX/XX/XXXX, I asked for her extension, but she said she would call me " she always calls her customers back ''. She never called so I called XX/XX/XXXX s/w XXXX  and she said my fees are a combination of the reduction and my paying my payment late. I told her I don't pay my payment late ( This is the second issue ) on the BMO Harris web site I go in on my XXXX day of my grace period ... payment it due on the XXXX and I pay on the XXXX, I log on to their website on the last day of the grace, but their system adds an extra 2-3 days to process. When I look back in their system about payments it looks like they were paid late, but I pay on time, they process late, and there is no way to change the date they decide to process on their website. I feel they do this on purpose to scam and get late fees out of people. I went on BMO Harris web site today to make my payment... mind you last month I only had to pay {$290.00} something verified by the collections dept on XX/XX/XXXX which I paid {$300.00} XX/XX/XXXX, now it said I owed {$1400.00} which I pay {$630.00} was reg payment the rest I have no idea???? I called today to BMO s/w XXXX to ask about the late fees of my original issue and now why am I being charged all this money for my monthly payment? She put me on hold said she had to s/w someone in the payment reduction dept, then she came back online and told me she was waiting to hear from someone, then I asked another question and she said even though I pay on the XXXX day of my grace period I am being changed 0.3 % daily after the XXXX ( when my payment is due ) I said I have never been told that before and have had several loans over my lifetime. she then said she was going to try the collections dept ( now a different dept than before ) she had me on hold then she never came on the line she put me in a cue and it was to a dept that was not open, she had my phone number and never called me. I told her I wanted to get taken care of today. I paid {$1500.00} today. My fear that is not the late fees either. I need help with these late fees I pay my payment on the last day of the grace, but they take 2-3 days to process. Also I should not being charged late fees during the 3 month reduction since they approved this plan.