Your phone can't receive Caller ID data from the network when it's offline. And CIDs for "missed calls" aren't stored for pending notification (like network SMSC storing undelivered SMS messsges and MMS attachs). Canadian consumers can't even subscribe to third-party services (like TrapCall) because the CRTC imposes protected "privacy" controls.
https://en.wikipedia.org/wiki/Caller_ID
Voicemail automatically stores incoming numbers (unless they're unknown, blocked, private, etc) along with time/date and other message envelope information. You can get the computer babble to methodically play it out, there's a setting somewhere in the user menus.
And the callers can always record a message to identify themselves and their contact information. If they don't bother then it's probably unimportant. If it is important then they will call back.
If you're on a Limited minutes plan then retreive your voicemails by calling your own phone number (and entering yoir PIN) from another phone line.
