Not cancelling and re loading debit orders

Ok so I was phoned by Platinum life who wanted to know why their debit orders were unsuccessful, I told them that I wanted to cancel the policy for them as I could no longer afford it. This month a debit order for 3 months worth of premiums was debited from my account. I did not authorise this debit order as I want to cancel this policy due to affordability! For once and for all stop debiting my account. if this persist I will give you over to the National credit regulator for reckless credit and for debiting with out authorisation!