Not exactly sure where I got this from, but I once read: "Call me - it's simpler" translates to you wanting to do your thinking inside my ear instead of your head.

That being said, from my own experience, the only thing that phone calls get done like no other medium (apart from a direct conversation, of course) is build interpersonal trust. It can further be a good way to diffuse tension right away because instead of having a customer write pages of mounting tension, they get a reaction immediately and that alone is usually enough to make the first steps towards reconciliation.