calling the mother seems to be breach of privacy unless the son gave the mother's info as a contact. Say my son and I are both ATT customers. They know we have the same last name but beyond that they do not know we are related.
I'm the primary account holder (my ssn), but mom is on the family plan. I'm sure they didn't know they were calling my mother, just picked someone else on the family plan and dialed it.
Anyway, I haven't heard back from them at all today. We'll see.