My sister has a oral visitation agreement with her soon to be ex-husband. It seems he keeps playing these games when it comes to returning their son at times estipulated. The child has "interrupted" schedules during the week when it comes to during the week stays over. He knows he is not suppose to have the child overnight during school week but he decides out of the blue to do it and when my sister goes to pick him up he disregards her presence and does not answer the door. This causes a lot of distress to her. She has a lawyer but she just calls him not to repeat these situations, but he still continues to disregard agreed rules. What else can my sister do to reinforce structured rules that he needs to follow. Please, she needs further advise. Thank you.