I have a personal greeting recorded which I want to delete and so just use the standard O2 one however there seems to be no option in the settings to do this?
I tried recording a new message then deleting it when given the option to retain but it reverted to my original personal greeting.
I've also tried cancelling the voicemail service by dialling 1760 then restarting by dialling 1750 but that still uses my original recording.
Finally an answer - You need to go into your personal greetings and re-record a blank message (that is complete silence) then save it. The O2 voicemail greeting will kick in. I've tested this and it works!!