CGHS, Aadhar Card & Empanelled Hospitals

In Delhi NCR, beneficiaries of CGHS are facing a peculiar problem. Many empanelled hospitals asking for both cards- Aadhar and CGHS, when they go for treatment. The hospital says CGHS is returning bills by raising objections to why ID( Aadhar) is not attached with the bill. They also complain that either CGHS or the Health Ministry did not issue an order in this regard but raising objections on bills. The CGHS has no convincing reply . The question is why CGHS card holders are being asked to provide ID when the beneficiary is having the CGHS ID?