my voice mails take weeks to come to me

Hi Folks - first time here - my voice mail does not notify when a new voice mail is left.  I just received 9 emails today March 22 - 2023 - the oldest being from Dec 30th 2022 - why am I not being notified and why do I get a big dump 3 months after the voice mail is left me?  Any ideas on how to fix this would be appreciated

Colin