I phoned them 1st week of November to cancel my insurance because i don't have a car anymore, the consultant assured me that the insurance is canceled

I phoned them 1st week of November to cancel my insurance because i don't have a car anymore, the consultant assured me that the insurance is canceled. Today i received an sms from them telling me that i missed the premium for November. I phoned them again today to cancel it, the guy i was talking to he offered to call me back so that i don't waste my airtime and he did not bother to call me back. I am fed up with this back and forth situation. I want the insurance cancelled and i don't think i will ever do business with you guys.