If you are one day late with your interest payment

Hello there,
I have a few payday loans that I have been paying on for quite sometime. Of course, they always call me when it is getting close to paying them each month. This month I asked if it would be okay if I came in on the day after my payment is due as it was impossible for me to get there on the due date this time.  I have always been prompt with my payments so far - never a day late. Well, needless to say, even though I was told it was fine to go ahead and come in that day, they sent my check through anyway and of course, since I have just gotten paid, it was paid. "The money was there, so we just went and got it," she said. Even though the lady said that it was fine to come a day later, there is nothing I can do now, is there? I called the regional, district (?) manager was called a liar because it was due that day and only that day.  I even went today to pay it (which was the day that I said I would be in), but they had the doors closed and locked - in the middle of the day!
I kind of want to tear my hair out. I thought for sure that it would be fine. I've already paid on my loans this month, but I have got to start next month and try to get rid of them somehow and beg for payment plans.