Sad to know that you have to go through all this with yoor Son. Many above have suggested to seel legal help or get people to mediate; this will not work for sure. I suggest you take a step back and think for a amicable solution. Reporting the certificates to his compnay will on,y gain vendetta. Frantically trying to get in touch with him will have him feel more insecure and important. These matters need time to mature, its like the wine process. Dont stir it to much else you risk spoiling it. Its easy for many to say- go to the court, speak to the parents etc etc. Think how does it help, you get him back or get him to help you morally or financially. You know him best, chalk a plan, implement it in phases, if one phase works out they try the second. All the best. Refrain from involving too many parties or its inevitably over.