In which it’s actually my own damn fault.
Apparently I let my computer auto-dial the long distance number to my ISP from 8/21 through 9/10.
This is so unlike me. I mean, I work at an ISP, I know better than to call Fairfield when I can call Douds for free. I only ever dial the Fairfield POP to troubleshoot connectivity problems!
Anyway, long story short: my phone bill, usually less than $30 per month, is $225.45 this month.