Harrasment and incompetence

Firstly i would like to know why NDS is calling me as the contract has been fully paid and closed months ago. NDS harrasses me on a daily basis by calling repeatedly at odd hours of the morning throughout the day and untill late at night. A bunch of *********** idiots as i have been decently trying to assist them but they cant seem to understand that their records and their company are THE PROBLEM! My last call with them had a vulgar call centre lady on the line. I would appreciate if someone could burn this company to the ground. Maybe that wpuld be the only way to get them to stop calling me. I HATE NDS!!!!!!