From what I understand this is my exact situation.
My maternal grandfather was born in my native country (Canada) my maternal great grandfather was an Italian citizen at the time of his birth. No one has renounced their Italian citizenship so I qualify according to
www.myitaliancitizenship.com. I figured a phone call would be the best bet. It's pretty overwhelming as you need to fully document the chain and a lot of the documents need to be translated into Italian.