Office 365 and junk email retention policy

I am using Office 365.  Clients are Outlook 2010 and OWA.  What I am trying to do is set the retention policy for the junk mail to be more than 30 days.  Say 45 days.   What I've done so far is add a retention tags called Junk Mail 45 days, type is Junk Email, Retention Period is 45 days and retention action is Delete.   I then remove the Junk Email tag in the Default MRM Policy and added this new one.  

When I login my account via OWA, right click on the junk mail folder, and click on assign retention policy, it still show the standard Junk Email (1 month).    Why is it not showing the 45 days.

Thanks for any assistance with this.

Regards

Vince