Is your entry in the Monash Internal Directory Service (MIDS) up to date and accurate? If not, people can't find you!! Take a look via https://mids.monash.edu.au/.
If not simply log a request via Service Desk to update your entry. Head on over to Service Desk Online and select 'Phones, Faxes, Mobile and Accessories' and then 'Add, change or delete my details'. The efficient Service Desk team usually turn around the changes within half and hour.