Outlook saying it is locked

This bizarre situation has now gone on for a few days. My account *** Email address is removed for privacy *** is locked because - wait for it - I merely attempted to send an email. So I went through the SMS verification it demanded and each time, it still refused to send the email. Eventually it said I had tried too many times, try again tomorrow. So I did. Same result. Can someone please advise how to unlock my account so I can get on with the urgent business of sending emails on behalf of my THEATRE COMPANY PLEASE!!! It is very frustrating to be prevented from doing normal things because of excessive security.