Your plan is renewed at noon the day before the anniversary date of your payment cycle. If your next cycle starts May 5, payment for that cycle will be taken on May 4 at noon and it will be taken from your credit card.
The only way to change your date is getting suspended for a day If your plan is suspended by Fizz, whether for purposes of analysis following inappropriate use or following non-payment, your payment cycle will simply shift. For example, say the plan of a member is suspended following a missed payment, and Fizz ends up receiving the said payment 5 days later. The payment cycle of this member will simply be shifted by 5 days. He’ll enjoy his plan for a month, and the new anniversary date of his plan will become the day Fizz received that payment.
The information are taken from this page
The only point I will add is that the payment is taken from whatever card you have as method of payment.
If you are using Visa Debit or MasterCard Debit and you have insufficient funds in your bank account, it depends on your bank plan. Some plans allow you to overdraft (although there might be a fee for this). Whereas other plans will simply reject the transaction.
If you are using a credit card, the charge will usually go though if your card is in good standing.