Refuses To Let Me Cash In My Rewards Balance

Several years ago, Capital One gave me the option to keep my account open at 14.90% or close the account and pay off the balance at 6.90%. Of course, I chose to close the account! Who in their right mind would pay an increased rate of 7%? I called them today and tried to cash in my rewards balance of 6,920 points, however they are stating that since the account has been closed, I can not cash them in. Please note that I have paid on this account EVERY month and never been late. The balance is almost paid off. I am no longer going to pay on this account. DO NOT GET A CAPITAL ONE CARD! THEY ARE ASSHOLES TO DEAL WITH!