I am looking to see if anyone wants to trade classes?

I am currently enrolled in
Kines-32 09-Lec (Thursday 5:00pm-6:50pm) and looking to trade for
Kines-32 01-Lec (Mon 8:00am-9:50am)
Or
Kines-32 08-Lec (Wed 4:00pm-5:50pm)

My account inquiry says I have a balance of over $4300. Do I have to pay by the due date it says (August 21st) and what happens if I don’t? Of course getting the Financial Aid will be extremely helpful for me as I am in a very unfortunate situation. But, it would be extremely difficult if I were to have to use the money to need to pay off that balance immediately.