Someone I don't know has a Comcast account at my address...

I don’t know the person in question. Someone from Comcast left a notice on my apartment door about the service being disconnected-except that I myself turned off my cable a year ago, and thus have no cable box.

I opened the latest bill, and the current balance is $550. I don’t want to go to the nearest Comcast office, tell them about this, and then have the zing me for the bill, but I’ll have to talk to them in any event so that I will stop receiving this woman’s bills.

What latest bill? If you turned off cable a year ago, why are you receiving any bills from them?

Wait, you said “this woman’s bills”? So you’re receiving misaddressed mail? Why are you opening it instead of marking it return to sender and putting it in the mail?

“Not at this address” and back in the mailbox.

They may be using the old account for training purposes. Somebody reactivated it and scheduled it for cancellation just to see how it’s done, and hit the Submit button a few times too many.

Because I’ve been doing that for close to a year now, and it still keeps coming.