Is it legal to discuss maintenance of a child with the employer of my ex-husband?

Hello.

I would like to know if it is legal or illegal to contact my ex-husband's HR dept due to his refusal to pay for child support since the birth of our child (Age 16 now). He lives and works in Dubai.

I have remarried and have other children, moved to Abu Dhabi 1 1/2 yrs back and contacted him at his office. He has failed on every promise until now. I cant afford the high legal fees to file a case.

Please, let me know what are my options. Thanks.