Capital One Credit Card Complaint

Capital One Credit card department,

Late fee Georgia

I am writing in regards to Capital One Platinum credit card. I received an offer for a new Platinum credit card in the mail about a year ago. It had a - percent balance transfer offer. I calculated the amount I would need to pay in order for me to pay off the balance completely by the time the introductory rate would begin. I began making $ 500 monthly payments to the Capital One account on a monthly basis. I was told when I opened the card that I was allowed to pay the balance in advance with no penalty. After paying the - monthly payment to Capital One for about 6 months, and never hearing from them via phone, email, or mail, I logged on to my account to see what was left of the balance. To my surprise I was billed a late fee for numerous months. Having made $500.00 payments for approximately 6 months I should have been paid through the end of the year. After calling Capital One I was informed that they do not allow consumers to make payments in advance. How is it legal for Capital One to not allow me to pay in advance. I pay my car loan payment 3 months and I pay all of my other credit cards 1-2 months in advance. I have never had in institution tell me that they do not accept payments in advance and regardless of timing if they do not receive a payment by each months due date, even if that amount has already been paid in advance, that they will bill me a late fee. If they have received the funds and I am paying as agreed how can I be assessed late fees on monies already received by Capital One. How can this be legal?