I often see sentences similar to: "Ich rufe sie sofort an."
My instinct when I say/write things like this myself would be to say "Ich rufe ihr sofort an," because in my head I think of "sie" as meaning "she" not "her." I know this is incorrect, but how do I chose the correct form?
Is it because "sie" remains "sie" in akkusativ, and only changes to "ihr" in Dativ?