If a member has been charged for two memberships, you should first check whether the member has two active memberships.
Go to the member’s profile and check the active memberships.
If an additional membership has been created, open the revision log for the membership.
Check the revision log to see when and by whom the additional membership was created.
If the membership was created by mistake, the additional membership should be removed or deactivated so that the member is not charged twice.
If you cannot determine the cause, or if the member has already been charged twice, escalate the case to a colleague who can help investigate the issue.