You may wonder if disabled or deleted staff user accounts on Kayako Classic are still included in your bill. This article provides the answer to this question.
If you disable or delete a staff user account, that will only prevent the user from accessing the account or instance. But, it does not remove it from your purchased seats. So the answer is yes, are you still paying for it unless you decide to remove the seat from your account totally.
To adjust your seat counts, check out the Adding or Removing Seats for Kayako Classic Subscription article.
Please note though that disabled staff user accounts are not counted against your seat count. This means that if you purchased five (5) seats for example, and you have two (2) staff accounts currently disabled, you can still create and activate two (2) new staff user accounts.