CLOSING MY ACCCOUNT

Okay, Supersonic is not a bad service, I have been with them for over 3 years, with problems what so ever, not one's in 3 years. BUT I change my service to a fiber package with another company, I did cancel my account with Supersonic, a month in advance, it is , 5 months later and over 20 emails, and my account is not closed, know they expect me to pay R3999, I WILL NOT, I canceled they services with 30 day in advanced notice. SO IF ANY ONE CAN PLEASE HELP ME, TO CLOSE THIS ACCOUNT, PLEASE EMAIL ME,