I have purchased credits in the past.

I just renewed one of my teams for another season, which brought my credit total down to 5. I am now seeing ads again.

Do I have to purchase credits AGAIN to quit seeing ads? I expected this would be a one time requirement.

Each season runs for approximately 3 months and costs 5 credits. To prevent ads from displaying, you must keep your credit balance above 5 credits. Depending on the league, credits may also be used to customize your team as well as rename your newly drafted players. To perform customizations, you must have a minimum balance of 6 game credits. If your credit balance drops below 5 credits, it will be brought back up to a 5 credit balance within 24 hours, allowing you to play in as many leagues as you like without having to purchase credits. Note that if your balance is above 5 credits you will not receive this credit reload.

My assumption is then the credits purchased are also used to renew for future seasons as well?

In other words:

Credit Balance: 6
Season Renew: -5
Game reloads: +4
Balance is back to 5 .. but more credits need to be purchased to avoid ads

Is this correct?