Late Payment Fee

I was not aware that there was a late payment fee for the tuition bill. Before I started classes in the fall, I had communicated with the financial office about delaying tuition bill payment for the fall semster because my family was going to be out of the country for the whole summer, and the university said it was fine. I assumed that it was fine for the spring semster as well, which was not the case. My family is in a tight finiancial situation. If I had known about the late payment fee, I would have made efforts to pay the tuition on time no matter what. What can I say to the university to have them possibly remove the late payment fee?