Without a court order there is nothing to enforce. Within pretty broad limits, both parties can do quite a lot until there is an order in place. However, unilaterally depriving the other parent of visitation or phone calls can be extremely detrimental to your custody case later. You need to talk to a lawyer to find out what the conditions are with your company relationship before you go about withholding any visitation from the other parent.
Technically, you would not be violating a court order if you withhold visitation until the court date. Query whether that's a good idea though. If you need help understanding your options and the pros/cons of a particular course of action, you need to consult with a family law attorney. No one can answer such a broad question with any degree of competency without more facts. I am including links below which will help you understand how best to prepare yourself for the upcoming mediation and custody hearing. Good luck.
If you found this answer helpful, let me know by clicking the "Mark as Helpful" button or "Best Answer" at the bottom of this answer. By answering this question, the Law Offices of Cathleen E. Norton does not intend to form an attorney-client relationship with the asking party. The answers posted on this website should not be construed as legal advice. The Law Offices of Cathleen E. Norton does not make any representations about your family law matter, but rather, seeks to provide general information to the public about family-law related matters. You should consult with an attorney to discuss the specific facts of your case. Thank you.