I had a Capital One checking account linked to a checking account from another bank. Last year, I closed that external account for security reasons and opened a new one. This year, I opened a Capital One credit card, which was automatically linked to the same online profile I previously used for checking. When it came time to make a payment on the new credit card, I saw a checking account already linked - so I used it without thinking. Unfortunately, it was the old, now-closed account. The payment was rejected. I immediately corrected the error and paid from my new, valid account. That’s when the nightmare began. Capital One started asking for endless documentation - one request after another - with each review taking 10 business days. I complied with everything they asked for, quickly and fully. After two months of this back-and-forth, they abruptly closed my account with no explanation. Let me be clear: I’ve never missed a payment. I have perfect credit. And this is how Capital One treats responsible customers. They’ve permanently lost me as a customer. I will never use another Capital One product again, and I strongly urge anyone reading this to think twice before trusting a company this careless and incompetent.