Hi Pearl1960
Thank you for those details
You should receive a new PIN by SMS.
This will need to reset this after receiving the SMS, by calling your voicemail.
The following points are guidelines for setting up a new PIN:
Not be purely repetitive,eg.7777
Not sequenced up or down,eg.1234,4321
The PIN cannot be a significant part of the Mobile number
Virgin Mobile default PIN(7890) will not be allowed as a sequence
New PIN's must be different from the previous PIN
Gareth_L