Your best option for international calling from Canada is a prepaid telephone card. You can dial the access numbers using the Fido SIM. However, it is much cheaper to call the access number from a pay phone (free), hotel phone (usually free) or “private” house (free).
I use the “Call World” card available at 7 11 convenience stores. The rate for calling a German (and most European) landlines is less than $0.05 per minute while a German mobile is $0.42 per minute.
A cheaper alternative is the "CiCi"
CiCi Phone Card card also available at 7 11 convenience stores. The rate for calling a German landline is $0.03 per minute while a German mobile is $0.20 per minute. Its minimum value is also $5.00.