Would you mind sharing a bit more about what happened or what the charge looks like? That’ll help point you in the right direction.
Unexpected charges usually happen when more paid seats are added than expected. If no seats are available, new seats must be purchased, causing extra costs. On annual plans, added seats are billed monthly. To manage this, review and downgrade seats to free View seats or adjust seat approval settings to control seat additions. Charges may be prorated based on approval date.
In the meantime, you might want to check:
your current seat count and usage
whether any new editors were added recently
your seat approval settings (to prevent automatic seat additions)
These guides might also help explain what you’re seeing: