I am trying to access my voicemail, at the recording it says first to select language, next to enter mailbox no. So I enter my phone number and press the star key but the system does not accept this to be my mailbox no. Please let me know what the 'mailbox' no. Here means.
I'm guessing you recently changed your number? That message generally means that you're connecting to the wrong VM server because the access number in your phone is wrong. Tech support would need to look up the correct number. They can then push it to the sim card, although I generally prefer to update it manually, (pushing it remotely doesn't always work).