What happens if one side interferes with the custody or visitation that was ordered by the court?

If a court order gives certain custody or visitation rights to a party and the other party fails to obey the order, the complaining party may file a petition alleging a violation of the order. After the court holds a hearing, the judge may change the order and/or impose sanctions on the party who has failed to comply with the order.
You can use the free and easy DIY Form program to make your petition to ask the Family Court to take action against the other parent who fails to follow the custody/visitation order.