Ok........so you could do either of these........
1) send them a full cease and desist. This will stop ALL collections/communications and I seriously doubt they would try to sue you over $177.00
2) You could send them a debt validation letter with a LIMITED cease and desist(there are samples in the beginner's section)......you could even do a
1 2 punch.
If you send them a DV with a limited C&D........then, by law, they have to cease ALL communications and collection activity with you until they can prove it's your debt. I seriously doubt they have proper validation.
The way they've ignored you in the past and kept sending you a bill........I wouldn't put it past them to ignore your DV and just send you another bill. IF they do that, they are in violation of the FDCPA and you could sue them for up to 1K just for that. That would at least give you the leverage to make them go away.