I had a bill like (but not) a disconnect fee I was determined to never pay.
A long time passed and I forgot about it, but one day a collection agency called.
I asked what had taken so long? But I wasn't paying. They threatened to sue, and I said I had been waiting years to get to court on this bill. I was a lawyer and would do my own work, and intended to subpoena a number of folks from the company and keep them on the stand all day. I also would have a counterclaim. But I wanted to defend, not sue (cheaper, easier, and a better position). So get on with the lawsuit ASAP, I could hardly wait for the fun to start.
Well, I got a lot of silence, and then.....
I've been dong this a long time, and I can't remember anyone asking us to hurry up and sue them. Well get off your ass, and by the way you'll need to file in Fairfax County Circuit Court. And BTW, if you list this as a bad debt on my Dunn & Bradstreet (credit rating), I'll sue you too. Funny, I never heard another word from them (nor did my credit record).

I'm sure they got back with the Co that sold them the debt and talked about them getting their CEO subpoenaed for all day on the witness stand.
(I cannot recommend this as a tactic for everyone, but if you are sitting on a winner of a case, it's one way to go.)