Make sure the transaction has posted to your account. Capital One can't help you with a transaction that is pending. The easiest way to do this is online. If you don't have online access, you can easily enroll on ouronline bankingpage.
See Also
Capital One 360 Checking® Account Review | The Motley FoolWhy Is Capital One Closing Branches?If the transaction was authorized but you have a concern with the service or product, you can try to resolve your dispute directly with the merchant. If you’re unable to resolve things with the merchant, you can give us a call at 1-866-536-9023 from 8am - 11pm ET Monday-Friday or 8am - 6pm ET Saturday.
Please note:If you are trying to dispute a non-merchant transaction (like a bill payment to an individual or a transfer) please give us a call.
