The phone number for the Commerce Bank credit card customer service department is (855) 659-1656. Just follow the prompts and you will get in contact with a live representative who should be able to answer your questions or direct you to the appropriate department.
Other ways to reach the Commerce Bank credit card customer service:
If you can't or don't want to talk to the Commerce Bank credit card customer service over the phone, there are a few alternatives. You can log in to online banking and chat with a representative, or send them an email.
You can also check Commerce Bank's FAQ page to see if there's already a solution to your credit card issue.