In AT&T's favor, I got a response to my message, in a slightly apologetic tone, telling me that the bill I saw was automatically generated, and that I should wait for the adjusted one which will pop out in a few days.
Still, I can't help but feeling that something in a system is wrong when you're posting bills that you then tell people to ignore.
Dammit. I ordered the empanadas again. There goes my weight for the next week...