When I cancelled my home braodband contract a while ago (because I was moving), I eventually ended up with a debt collector after me because they had kept billi

When I cancelled my home braodband contract a while ago (because I was moving), I eventually ended up with a debt collector after me because they had kept billing me. They had also disconnected me, connected someone else at the same property with the same cable, billed them and been paid by them, so they were not only billing me after I had cancelled, they were billing twice for the same connection. I tried csalling their customer services to sort it, they were no help. Eventually one of their agents admitted there was nothing they, or anyone else I could call with a publicly available number, could do. (Edit: I forgot, I had also sent recorded delivery mail about it, but got no response). I eventually got it resolved by finding the number for the CEO's secretary or someone, and harassing them about it until they got it sorted. Now, the same thing has happened with Virgin Media Business at work (I cancelled because it was always going down, including the PSTN phones, the service was awful and we no longer need it - we had it before I joined, they have been billing us for months after we cancelled). Worst ISP ever.