@Chris *****
What do you describe as a work visa, is that the Non Immigrant B visa you bought from the Embassy before you made your way into Thailand and are still on the initial 90 days,
OR
Did you convert your tourist visa or visa exempt into a Non Immigrant B visa at Immigration and are still on the first 90 days
OR
Did you visit Immigration and got a new stamp with the text Extension of Stay is permitted up to xx.xx.xx
Totally different things with different rules, regulations and requirements and I hate to guess which one you have.