Go to Medaille.onthehub.com, Sign In and go to My Account.
Under your Order History click on View Details, your key will be listed there.
More Help with On the Hub Microsoft
For more information there is also a help section link in the upper right hand corner of the page.
Live customer support agents are available to assist you Monday to Friday between 6am and 6pm EST.; call waiting time varies by time of day. USA/Canada (Toll Free): 1-888-396-1447.