@Mandar, it depends on the type of service you have linked to your My Account. For example; Optus Cable services self-serve functionality is limited.
THERE ARE SOME DIFFERENCES WITH CABLE SERVICES WITHIN MY ACCOUNT
The Optus Cable Network (i.e. Cable Home Phone, Optus TV feat. Foxtel and or Cable Broadband) uses a different billing system to most of our other services. So some functions within My Account will operate a bit differently to your other services in My Account, including: