I received an offer from Capital One for convenience checks with a promotional rate of 5.99% as long as checks posted by 11/15/2010. So I wrote two checks on 11/7. The first posted to Capital One within a few days and I received the promotional rate on it. The second posted to the Capital One card on 11/15. When I received my statement though, I did not get the promotional rate even though the mailing clearly stated in multiple places the offer was good through 11/15. Thankfully I kept all the paperwork. So Capital One is INCORRECTLY charging the wrong interest rate on this transaction, a much higher one of 17.9%. I phoned Capital One and was on the phone for 30 minutes with a representative stationed God-knows-where who could not help. The supervisor he transferred me to was better; she is sending this over to another department to review. Just in case that is not enough to get this corrected, I just wrote their "disputes" department, and am sending copies of all the paperwork I saved, including the initial offer which clearly states "must post by 11/15. Here\'s what I am sending them, minus of course the dollar amount and other information that is personal. And my caveat to you reader, is to save paperwork and check your statements carefully, especially when dealing with Capital One. I am writing to notify you that you have made an error in the interest rate being applied to the transaction dated November 15, 2010. That check qualified for a special transaction rate. Please see the following attachments: Attachment A – copy of letter from you "Dated Notification" . It states "Act by 11/15/2010 and get a 5.99% APR for 12 months. It also says "limited-time"…. "must post to your account by November 15, 2010. Attachment B – copy of second part of letter from you, right above the checks you sent. See the section titled "Use-by-date"; it clearly states "these checks must post to your account by November 15, 2010 for the promotional APR to apply. Attachment C – copy of statement from you showing that the check for $xxx posted on November 15, which means it qualifies for the 5.99% interest rate. Please rectify your error immediately, adjust the interest rate retroactively to the 5.99% rate that should have been charged. Otherwise, I will be taking legal action.