Does anyone know to whom or what agency to contact in regards to reporting credit card
Complaints against a credit card company?

I will check into this and let you know, Thank You.

Where do you live and what's the exact complaint?

Hello, first you responded one minute after you asked the question,
The experts here are not always online, some come every day, others a couiple times a week, so you will be getting various answers over the next week.

But you did not give a lot of info, complaints about a credit card would normally go to the management of that credit card company.
You can report illegal activities to the attorney general of your state, to the BBB and other consumer groups.