I am travelling in the states and switched my Koodo Canadian sim card in to a second iPhone. I discovered today that while it receives calls, those calls are no longer going to voicemail. As in my voicemail has completely disappeared. I can't access it and when others call me the phone just rings and rings and never goes to voicemail. I recognize that I am roaming so I can't use visual voicemail but people should still be able to leave me a message. Any ideas please?