Upgrade to 500 / 500 service

Today I chose to upgrade from 300 down / 35 up to the 500 down / 500 up / unlimited data service -- however after the order went through it updated to 500 down / 35 up.  How do I get this corrected?  (I did try the Xfinity Assistant and it gets confused thinking I have an outage.  I haven't found where I can open a customer support case.)

Thanks,

Nathan