Contact between my child and his dad is strictly limited by court to supervised visits only at a communication centre (following findings of a court appointed expert that he is physically and psychologically dangerous to our son). Despite this, his dad

Contact between my child and his dad  is strictly limited by court to supervised visits only at a communication centre (following findings of a court appointed expert that he is  physically and psychologically dangerous to our son). Despite this, his dad keeps trying to make phone contact from various phones.  What can I do?

File for a court order (injunction) to prevent the father trying to establish phone contact, or any contact other than that ordered,  with a built-in penalty for breaching it.  If the father breaches the order, you can file for contempt of court – and the court can fine or even imprison the father if he persists.