I have been having similar experience. I have never been late and have always paid more than the min payment.
I recently paid off the balance - only to discover that they added "interest charges" after I paid the balance. It was less than 2 dollars and I caught it and paid it before the due date...so still never a late payment. That was irritating enough...but the interest rate is incredibly high for someone who never missed a payment over the years. I have stopped using the card completely and will see if they tack any interest onto the interest next month.
Regardless...I am considering simply cancelling the card and account completely.
I only got it to help improve my credit score which is very good. But since I don't generally use credit...not sure it is worth it at all.
Product or Service Mentioned: Capital One Account.
Reason of review: interest rate increases.
Capital One Cons: Ridiculous fees.