Does not Cancel Policy

I sold my car last week Monday, logged a call on Tuesday morning early to cancel my policy. Operator told me they will send confirmation and stop debit order 31ste they deduct a premium for November. have been trying to call since Monday. placed 3 call me backs. and send emails. today they send a message they cant get hold of me. I call them back. they tell me my policy is still active, no sign of cancelation, but they cant assist some one will call me back.