Christian Medical College — regarding pathological investigations

Sir, my card no is 790180d. Yesterday i was visited to orthopaedic and medicine specialist. Both are advice for same pathological test. But i didn't know what is they're written in my prescription. When i was going to cash counter, they are charge me for same test twice. When i ask them for refund my amount they told me that it's not possible. What can i do sir? Once all the investigation done what is the requirement for repeated it. If not required then refund my amount. Please help me sir. We have lot of faith about cmc don't break it.