I had a 13 dollar balance on my credit card one month, but the minimum payment each cycle (unless I have a balance of zero) is 15 dollars. I tried paying 15 dollars, but it would not let me pay more than my balance. So now I have a late fee for not paying off the minimum payment.

Great. With the 19 dollar late fee I can definitely pay off my minimum payment now! That, by the way, was raised to 25 dollars. THANKS.