Recently I faced same issue with SMS for my Digital Ocean account. Fortunately I have my backup code to restore an account. Finally I moved to authenticator based code. By the way, Digital Ocean support is much more better than Amazon.
Currently working on LeadMine https://www.leadmine.net - Find new prospects and their email address.
LeadMine is lead generation software for any type of business. With their powerful and flexible tools users can now find qualified leads along with their respective email addresses in seconds.
Using the capture feature, you can add and track all your prospects with a simple interface - will eliminate the use of spreadsheets. Once list is generated, users can then begin to contact leads and convert sales!