I can recommend one at the Stadium in Puerta Plata. The name of the school is Escuela de Choferes Jose. I have sent a few people there, and they all learned to drive and got their license.
You can go there, or call Miri at 809-913-8999. Tell Miri Ricardo sent you.
One more thing, you need to speak Spanish if you call her. If not, just go there and tell her I sent you.