The automated voice said:
Hi there. This voicemail is from Comcast Xfinity. We’ve received no response, and your 50% discount on monthly is now being removed from the system. This change is permanent and cannot be reversed. Call the number on your caller ID immediately before your billing returns to full price. Thank you..
The call out to use the number on the caller ID and not an official Xfinity support number is the giveaway for me.
I am not a customer of Xfinity by the way.