Can I hold my bank liable for debit order instruction that I did not authorized in any way?
I discovered that an debit order is being debited on my account, the company that is debiting my account is selling insurance, and that the policy belongs to someone else but is debited on my bank account.

Have you talked to the bank?

I would call the merchant and see if you can work it out with them and have your money refunded first. I only suggest this because each time I've had to call my bank about unauthorized charges they've told me to try talking to the merchant first. I haven't actually ever had any success with a merchant yet. But that's what my bank tells me to try first. Or have you already talked with the merchant? You could try calling your bank first. Worst case scenario is they make you call the merchant first and then you have to call them back. But your bank should have a fraud department that can help you.

If you can prove this was not your debit, you can request the money returned ( normally within a reasonable time.

Assuming this first started going out.