Never had service but won't stop calling

Never had an account and have no AT&T service. Made the mistake over a year and a half ago to set up installation but they wanted to punch holes in the walls and mount the dish on the roof. I rejected the install and yet they will NOT stop calling...repeatedly multiple times a day and at all hours. I have requested for them many times to stop calling but they don't stop. Driving me insane. Just made a complaint with the FCC.