Hathway — Hathway broadband calling unnecessary

I had ha hathway broadband connection and I have deactivated the connection but still I am getting daily call 3 to 4 time at day. I requested to don't call me again and again but they are not listening to me what I do? I have frustrated with this.
When I contact to some hathway person so they are telling me please block the number but how I can block the number everyday I am getting from the new number everyday.