Sam, hopefully they have given up on the idea of trying to collect this stupid false debt, but if you ever get on the phone again with a wannabe debt collector from the Co$, you could just politely explain that your next payment is not due until the 2980s. You could also say that you wouldn't mind if they sent you a reminder notice in about 970 years so you could be sure to fit that second payment into your budget. Then thank them for their time and hang up.
For freebies they are great. Of course they aren't spot-on and sometimes are hilarious, but they are a vast improvement on any practical alternative I have available.
In the Expressen article there was a promise from the CofS to remove me from their mailing list. Yet I got something from the CofS in Copenhagen in my mail. Nothing threatening, just a common stupid promotion piece.