Your voicemail might be set up to accept msg with a generic msg to people that call you... you might not have set up a personal msg but that doesn't means voice mail isn't set up - i'd call ur self and see if a msg can be left or not... I pay as you go comes with voicemail and i think is pre set up with gentric msg
As per: on rogers.com
How am I charged for Voicemail on my Pay As You Go account?
Voicemail is available with no monthly fee on the Pay As You Go service. Airtime charges (plus long distance and/or roaming where applicable) apply for messages left in your Pay As You Govoicemail and for checking your Voicemail messages. Airtime charges apply if you call a number and a voicemail service answers.