Taking money with no active policies

I cancelled my policy last month and a debit order for this policy went off for this month. After contacting them, which involved a 38min wait for their call centre to answer me, and asking for a refund on this *********, ******** and incorrect debit order, all they said is they cant help me because the policy doesn't exist (I have policy documents, so how can it not exists?). Regardless if the policy isn't active, it will exist as a paid out policy.