Voicemail deleted without my knowledge and saved VM have also disappeared

[DA-1]

My VM greeting has been deleted . It was sentimental ( my dog barking ) it’s no longer my greeting and I haven’t deleted it . Also my saved voicemails have also been deleted - or longer there . How do I access them . 

[PeteG]

Hello, DA-1. 

Welcome to the Three Community. 

In voicemail, I'm sorry to say that saved messages are only saved for around 15 days. After that, the messages are deleted. 

Pete.

[DA-1]

Thank you for the reply, are you able to tell me why my VM greeting has been deleted ?