- In that case, The operator is allowing customers to have their personalized mailboxes and that's why the customer didn't fall under the preassigned mailbox numbers because he purchased a custom mailbox number for x $.
The Operator can disable the option by following the below steps:
- Go to your Business Settings
- Click on the section titled "Plans"
- Click on the tab titled "Plan Conditions"
- Go to the "Allow users to select a personalized mailbox number", disable the button.