If you did not receive your scheduled SMS there are a few things to check. Check your Sent Message Log, which is located under Reports and Results --> View sent message log. Find your SMS and then check the SMS status.

If you can't find the SMS in the log then you should check if you had enough SMS credits for the send. Please note that if you are short of even one SMS credit, the system will abort the entire send.

And lastly, check if you have had any new customers sign up to your  database as this could have altered the recipient count which would result in not having enough credits for the scheduled SMS send.