If you have an agreement with "agreed times," then its not him who'd need to go back to court to modify, it's you. My advise would be to file a modification petition & ask that the order incorporate times when you can call the child when he's not with you as well as penalties if he cancels visits for no reason (such as forfeiture of the next scheduled visit). Schedule a consult with a NYC Child Custody attorney for a full assessment.  -- David Bliven, Bronx Child Custody attorney (www.blivenlaw.net