Lack of communication

So I cancelled with supersonic know the 15th September 2020, i received a automated emailing saying they need 1 months cancellation notice and that one of their agents will call me to finalize my cancellation .it is the 7th of October, after 5 phone calls with different agents saying they will each personally call me back after they have heard from the cancellations department no ONE has called me back which clearly means the cancellation department is lacking communication. On their system shows I cancelled the 22nd. Come end of October they going to send me an account demanding I pay cos of their lack or communication. Please have someone call me asap, I am not impressed at all