You did not tell us what insurance you are talking about, and why the bank (and not an insurance company) is sending you bills. If you own a house and have forced-placed insurance, or are otherwise required to have insurance on property you still have, the obligation to pay for the insurance is probably still there. You don't get continuing insurance for free. You need to tell us more of the story, or discuss with your lawyer.
I fear that you believe that your bankruptcy eliminated your ownership of property in which you stated that it was your intent to surrender. That is not the case. Unless the lender completes a repossession or foreclosure, you may still have the continued obligation to provide insurance for the property, you may be on the hook. You may want to re-submit your question again to make the details more clear, as I can only guess what you mean by "it." Hope this perspective helps!
What type of insurance are they billing you for? Do you own property that was included in the bankruptcy? Are you living in the property or is it rented? Was your case officially closed?
It sounds like what you're receiving are letters regarding force-placed insurance that your mortgage company has had placed on your former house. Presumably you filed bankruptcy on your house and surrendered it through your bankruptcy. When my clients get these notices we generally fax over to the company sending out the force-placed letters, a copy of the Notice of Bankruptcy, the schedule from your bankruptcy showing the house debt and the Notice of Discharge. This generally stops the letters. Good luck.