Here's info I happened to have handy from the US consular information sheet:
The Embassy is located at the corner of Calle Cesar Nicolas Penson and Calle Leopoldo Navarro in Santo Domingo; telephone (809) 221-2171; after-hours: (809) 221-8100. The Consular Section is a half-mile away at the corner of Calle Cesar Nicolas Penson and Maximo Gomez; telephone (809) 221-5030. Consulate office hours are 7:30 am -12:00 pm and 1:00 pm - 2:00 pm, Monday-Friday, except holidays. There is a Consular Agency in Puerto Plata at Calle Beller 51, 2nd floor, office 6; telephone (809) 586-4202; office hours Monday-Friday, except holidays, 9:00 am - 12:00 pm, and 2:30 pm - 5:00 pm.
they give no email address, unfortunately.
good luck.