You'll have to call someone. This is not the place to ask.
I'm guessing you are talking about the annual automatic renewal feature on a Barnes & Noble Membership, as this is the only thing that B&N offers as an automatic payment. (If you paid for the Membership with a Credit or debit card, they'll keep that card number on file for this purpose. A debit card is the only way they could be charging your checking account.) There are two easy ways to opt out. One is to call the Member Service number on the back of the Member card. The other is to follow the link provided in the email they send you 30 days before the renewal. If you don't have a Membership, or this is not about the once a year renewal fee, then I don't think this is a question about Barnes & Noble, and you should probably ask your bank.
Call your bank to stop automatic deductions.
Probably check the website and end whatever subscription you have
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