Wire down, but I am not a customer

A tree fell and took down a wire running from my house to the utility pole on the street, and it's now laying on my yard. The wire has a Comcast tag on it. I currently get internet via AT&T; the Comcast hookup was used by the previous owners but is no longer in use. Now that it's broken, this wire needs to be removed. Because it's marked as Comcast's, AT&T won't remove it. Because I'm not an active Xfinity customer, I can't report the issue online or get through the phone system at all.

I managed to get a hold of a real person via chat support yesterday, who said they'd have a tech come out today, but they never showed. (They also said I'd get a text confirming that appointment, and I never got that text.) Today, I'm unable to get past the chat bot to get a real person, no matter how many times I ask for a human or an agent.

How on earth am I supposed to get this cable removed? This has been an immensely frustrating experience.