One of the recent features added by Microsoft to Office 365 is the ability to add custom Help Desk information to the Office 365 Hel panel. To add this information:
Log into the Office 365 portal and click on “Company Profile”.
Then click on “Custom help desk”, here you can specify contact details for the custom Help Desk you want to use in Office 365.
Add Help Desk information and save changes.
The next time you do login in Office 365 portal you will have access to the Help Desk information in the Help card in the Office 365 portal.