I used it to attempt to cancel in early February. I cc'd in a few random corporate VM email accounts to make sure I had something in the system.In the past it was possible to give 30 days cancellation notice by email to cancel@virginmedia.ie but I don't know if that's still an option?
I was planning on signing up as a new customer to get the better rates but it didn't come to that as they matched the new customer offer.