Who to talk to when your company refuses to allow you to put your son on the health insurance plan due to no open enrollment?

All policies have specific rules for adding dependents. The general rule is either at open enrollment or when there is a qualifying event. That event might be loss of previous coverage, new birth or adoption etc. You are generally not allowed to add a dependent at will. One of those circumstances must be the reason and each has a specific time frame that must be followed.

If you do have a qualifying event and your employer is refusing to add your son call your state Dept of Insurance.