Looks like Smart Telecom have gone bust, when I try to dial a number I get a message your smart telecom service is no longer available and telling me to contact Comreg for alternatives - I knew they'd been having financial difficulties but just dropping service with no warning is a bit much. Luckily my internet is elsewhere but looks like I'm back on the market for a phone service.

Update: According to RTE it's a dispute between them and their wholesale supplier Eircom about credit issues which pretty much amount to the same thing.