Claiming interest for the delay in settling gratuity

I joined service in 1984 as hsa in dbhs, thrikkariyoor, kothamangalam (aided school in kerala) and retired as headmistress, dbhss, cheriyand on 30-04-2014. the period of service as hm from 01/04/2013 to 30/04/2014 was audited on 10th june 2014 by the dy. director (education), alappuzha and audit report was issued on 06/11/2014 (five months after audit). all the points were cleared by the present hm and consequently on 30/01/2015 dd requested the present hm to issue liability / non-liability certificate. accordingly the present hm issued the non-liability certificate. on 24/02/2015 dd again raised some more points that were not covered in the earlier audit report and all the points were once again cleared by the present hm and finally audit clearance was issued on 29/05/2015 and my eligible gratuity of rs.7,00,000/= was released in june 2015, without any compensation for the delay of 13 months after retirement. under the circumstances i request you to advice me whether i am eligible for compensation for the delay.