Earthlink billing

I have an earthlink dial up account that I use in two situations: when the cable modem is down (so far, rarely) and when I travel (see previous). Since I rarely use it, I didn’t want to pay a lot – so when I signed up for it (back when it was a “sprintmail.com” account via Sprint), I liked the fact that I had nationwide access for free (via local dial-ups) and only paid when I actually used it – unlike, say, AOL, where you have to pay no matter what.
I used it a few months ago when we spent the night at my in-laws, and apparently it was just after my credit card expired – they were auto-billing to my card (it’s MUCH easier that way). I probably checked my email, so the call was about 10 minutes – meaning it was less than a couple of bucks for the call. I didn’t think about it, until I checked that accounts email (something I only do once a month, since it’s 99% spam – despite earthlinks “spam-inator,” which allegedly would prevent this from happening. Whatever.) and saw a couple of official looking emails about my account.
It seems that Earthlink is a little irritated that they couldn’t bill my credit card for $0.89, so they were letting me know they were gonna cancel my account for me (they gave me a months notice, but it’s still a bit shocking).
They’ve also sent me two letters so far. The postage for the letters alone is $0.60, so they’ve spent almost as much money on me (assuming email is free, which it basically is) trying to get the amount due as what is actually due.
How freaky is that?