Procedure when moving a very short distance

My father lives in a senior community. He's moving from one apartment to another about .5 miles away within the same senior community. The ENTIRE senior community has a special contract with Xfinitiy that put all of the residents, hundreds of households, on  the same special contract. It's at Rossmoor, Walnut Creek CA. My father and other residents were given a special number to call for this, and told to use ONLY that number.

When he called there seemed to be nothing special about the service, or at least the rep wasn't aware. She did some things with him but he got confused and it seemed to leave the process incomplete. I think he set an appointment for May 2, to cancel serve at the old apartment and begin at the new, but it was confused.

I tried speaking with the rep and she had me give his Apple email, which they apparently used to start a new account and instructed him to provide more info for it on the iPhone app. That's when I took over; I could enter his [user]@comcast.net address and a password. But then it asked for phone number and/or email address. When I entered either the Apple email or his phone number I got rejected; the app said they were in use and prompted for another. Of course they are in use; they are on the other account and he has only one phone and email. Duh.

So I want to know several things:

1. How do I verify he still has an appointment for the move? 

2. For finding that appointment, do you need the account number and/or login info for the account we will be closing, or for the new one?

3. If we need the account number for the new address/account, how do I get that? Or is it not active yet?

4. Do we have to wait until the old account at the old address is closed before starting the new one? if so, I wish they hadn't started the process of making a new one. But he was told (as was I when I called the number) they have to set up a new account to even get the appointment. But we can't set up that account since we're using the one phone number on the old account, as well as the one email address. Catch 22. Could this waste more of everyone's time? :)

How do I straighten all of this out for him? I'd like to rant and say I've moving to another provider, but as I noted, Comcast/Xfinity has an exclusive contract where he lives. So we need to work together to solve this.

Thanks,

Rob