Can I retrieve a deleted voicemail?
No, unfortunately it is not possible to retrieve a deleted voicemail.
Bear in mind the timeframe on storing voice messages:
You can store up to 25 messages in your voice mailbox.
New messages will stay in your mailbox for up to 17 days. Any messages not listened to will delete at midnight on the 17th day.
Messages you have already listened to will stay in your mailbox for 14 days. At midnight on day 14 the message will delete. It is not possible to store or save a message in your mailbox for any longer than this time.
Some phones have a ‘call recorder’ option. This means that you can record audio that takes place on a call. You can use this service to record a voicemail by playing it back on your phone while using the call recorder function. This will enable you to store the message on your handset.