Voicemail Pin

I received a text today to say I had a new voicemail (which was odd since my phone had been sitting with full WiFi reception, didn't ring and no missed call is recorded).
I phoned the number given (07782333123) but am being asked for a pin number. I can't find where to add this on my account and when I phone, I am not prompted to set one up.
How do I set up a pin?
I phoned the number given (07782333123) but am being asked for a pin number. I can't find where to add this on my account and when I phone, I am not prompted to set one up.
How do I set up a pin?
0
Answers
We appreciate the advice however it may not be aplicable or we may need to further investigate on her account to make sure of what the issue is.
Its a nightmare and sure since I don't get notified when a new voicemail comes in (this was the case even with paying £0.99 a month for visual voicemail if the premium voice was used).
So I really should tell myself to call voicemail when I have a signal that isn't via Wifi. Then again I need those minutes to call customers for work if a VoIP System has really bad call quality even on a 20mb upload wifi connection.