How to check if a visa agent is legally registered in Thailand

Thank you for the detailed warnings about DTV applications using agents. One thing you said caught my attention, that some of the visa agents advertising online are possibly using fake business names or not legally registered in Thailand. Is there any easy way for us to verify if a visa agent is a legally registered company? I'm guessing that would greatly reduce the risk of being scammed, although I will definitely consider submitting the DTV on my own as suggested!