Can my boss turned down my request to see a doctor under workman's comp after injuring my ribs at work?

First, check the company policy manual or with the Human Resources department with your company in regards to injuries at work. Follow the company policy.

It would not be in the best interest of the company for your boss to deny you medical treatment for an injury which occurred at work. There are Federal and State laws covering workers rights under Workmans Compensation. You can also check with the Workers Compensation or Labor Board in your state.