Debit order going off after canceling the account

I cancelled my account on 28 December 2023, giving January as my notice period. And in February 2024, there's a debit order going off my account. When I called their accounts department, the lady confirmed that a cancellation request was received on the 28th but the person dealing with cancellation (Innocentia) made the effective date to be the 3rd of February 2024. So convenient, just after the debit order date. I've been calling asking to be put through to the cancellation department but no one is picking up any calls in that department.