Looloo,
I'm glad to hear the person who molested your child is in prison, where all child molesters belong. However, about your main complaint on contacting Bethel regarding what you perceive to be 'unloving' behavior of a member, please understand that the Organization shares the Biblical teachings with its members but it's up to the person individually to apply it in their personal life.
On the other hand, if I understood correctly based on what you wrote, you had an adulterous affair with their son, perhaps one of the reasons that got him disfellowshipped, then you moved away which made it the more inconvenient to see the grandchildren; you must admit that, with your own behavior, you've all created the scenario and now you complaint about it?! Look in the mirror, my dear, and own up!
DY