AZ child custody laws

court ordered visitation: My grandaughter's mother was allowed by the court to relocate from AZ to TN three years ago. Visitation provisions for my son were included in the ruling. All attempts by my son and I to contact the child and arrange for visitation were ignored both by the mother and the TN authorities. They have since moved back to AZ and have ignored all attempts at contact.
What do we need to do? She just seems to disappear when there are attempts at contact. Can I, as the grandparent do anything to force her hand? My son would gladly assign his visitation rights to me. - Is this your question? Add additional information