When you start, your account is setup with an initial credit limit of $50.
If you reach your credit limit before the end of 30 days, your credit limit is raised in increments. Your initial credit limit of $50 is first increased to $250, and then to a final level of $500. A new billing cycle begins each time you reach your credit limit or after 30 days.
On August 1st, Melissa opens a new account and starts accruing costs.
On August 5th, Melissa hits her initial $50 credit limit and is billed for the amount accrued. Melissa's credit limit is now raised to $250 and a new billing cycle begins.
On August 25th, Melissa reaches her $250 credit limit. Melissa is charged for the amount accrued and her credit limit is increased to $500. Melissa's next payment will be due on September 25th or when she accrues charges in excess of the final $500 credit limit - whichever occurs first.