Medical negligence

Hi, This side Shaikh M Shabbir from mumbai, my nephew was having 2/3 nodules(gaanth) in his neck we consult a MD for the same he asked us that he'll have to do a biopsy and cultural test to know the exact disease we agreed for both he admitted the patient took Rs. 7500 for both the tests.they perform the minor surgery with 2 stitches for the same. After 10 days when we contacted the hospital they said it will take time for the reports. After following up for almost 1 month lab incharge said biopsy was not done because it was required to put sample in formaline & doctor put the sample in normal saline because of that they can not perform the biopsy... And now they are asking to do the test again... Pls suggest how & where we can lodge a complain for this negligence because of this patient is still suffering. Later on we came to know that there were 2 more same cases were there in the same hospital where it had happened. Humble request pls let me know if it comes under medical consumer case or not if yes so please let me know the process for filing a complain or else should i try at court/police station??? Please help to save more cases. Thanking you, Shaikh M Shabbir