Hathway — Internet service customer calls

Hathway customer services have not stopped calling with new offers when it was told to them that I have a new connection and I do not want their services anymore.
This has been going on for the past year. My phone has not stopped ringing.
Even when I changed my number from their app also.
Have tried so many times to get my deposit back and for them to come to take away their modem and disconnect the service.
This is mental harassment. Their staff doesn't know how to talk. It is becoming a hassle.

I just want them to delete my number from their database and stop calling.