Are you paying the “Standard Rate” on your credit card? If you’ve been a good client (i.e. you haven’t missed any payments). Call your credit card company and ask them to lower your interest rate.
Do you have a credit card that gives you rewards like Airmiles or Cashback? If you take away these features and get a “No Frills” card that may automatically lower your interest rate, since credit card companies tend to charge a premium for these “special” cards. And, you may save extra money by forgoing an Annual Fee!