A real number's paid billing window is distinct from the number of messages you send. Keeping a paid number active can consume credits even when you are not sending traffic. Other chargeable actions and purchases are shown separately in the team's history.
Review the entries for the relevant period and number. Stopping a number prevents new active windows; it does not pause or refund a window already purchased. If you cannot match a deduction to the displayed activity, give support the transaction reference and time rather than reconnecting or deleting the number.