I cannot confirm charges or cancellation status from here, but if you canceled your Professional plan, you keep access to Professional features until the end of the current billing period, and then the team downgrades to Starter.
For the accidentally upgraded seat, new paid seats on Professional are added to the next invoice, and if your plan has renewed under the updated billing model, they can be prorated from the day the seat was approved.
Please tell me which page shows you being moved back to Professional—such as Admin, Settings, or Billing—and whether your subscription is monthly or annual.
