Disgusting service

I decided to cancel my DStv account due to their pathetic service and I'm know longer working I have not signed a fix term contract with these people yet I'm getting a call from Blake and associates for collection, please deactivate my account as I'm not interested in your pathetic service when I asked you guys to downgrade my service as I'm not working you guys could not help me you guys are useless and if DStv is like prepaid airtime why am I in arrears in the first place I have not signed a fix term contract,if this harrasment does not stop I'm going to need to take matters further