ADT Cancellation of an Account

As i have explained to various agents over and over again since last year August! I requested to cancel my account with ADT and called and sent through a cancellation letter as they requested. Ever since then the account has been handed over to an even more *********** company called DEBTSOURCE! I spoke to numerous agents trying to resolve the matter but still no assistance. I even asked them if they do not want my money that i am willing to pay. i want to cut all ties with this company and its *********** staff. All i want is to pay what i am liable for and resolve this matter once and for all.