To cancel a scheduled SMS campaign:
Go to Campaigns > SMS and select the Outbox tab.
Select the Cancel send icon for the message you want to cancel.
From the side panel, select Cancel send.
To modify a scheduled SMS campaign, you must first cancel the send using the steps above.
If the message has not been sent, you're returned to the Unsent SMS campaigns tab, where you can edit and reschedule the campaign.
If the campaign has been sent, you're returned to the Sent tab. To modify a sent SMS campaign, you must create an unsent copy.
To do this:
Go to Campaigns > SMS.
Select either the Sent tab.
Find the campaign you want to copy, and select the Copy icon
Enter a new name for the campaign.
Select SAVE.
The copy appears on the Unsent tab where you can make any edits you need before rescheduling.