Unauthorized Debit Order

Not midway ruining my day before it even begins, I called them on the 15th and asked to cancel my policy with immediate effect and I was told it was canceled, then to my surprise days later it was active. I called again and this time waited on the call for hours until they send me proof of cancelation and which they did now they have debited my account, meaning I will have a negative balance due to my other debit orders not getting money. I am so furious