New Apartment Address Not Recognized

I'm moving to a new apartment and want to get xfinity internet at the new location. 
My current location has xfinity pre-packaged in with the lease. 

I'm attempting to look into setting up a new plan at the new address, but the site returns the new address as an invalid address. 
The leasing agent said they know a number of people in the complex with xfinity service, so I'm at a bit of a loss. 

Investigating the issue seems to show that in the past people have had to reach out to get their address added. I tried doing so through the phone service, but couldn't battle past the automated help to talk to an actual person. 

Where or who do I need to reach out to to see about the issue? 

Thanks