At least one standard or model line with this line number already exists on this order. Please chang

Dear All,

My requirement is to create RMA order through API.

Successfully creating RMA order , but when trying to pass below information, in API ,

L_LINE_TBL(I).RETURN_CONTEXT := 'ORDER';

                L_LINE_TBL(I).RETURN_ATTRIBUTE1 := ORIGINAL_HEADER_ID;

                L_LINE_TBL(I).RETURN_ATTRIBUTE2 :=  ORIGINAL_LINE_ID;

The program is failing with below error .

At least one standard or model line with this line number already exists on this order. Please change the line number.

Without above 3 columns RETURN_CONTEXT,RETURN_ATTRIBUTE1,RETURN_ATTRIBUTE2  , successfully creating order.

But as per our requirement  RETURN_CONTEXT is required for client ,w e need to populate these 3 columns also .