Housing CHS interest dispute with society.

Respected Sir I would like to seek your valued advise .I am writing on behalf of my mother who is owner of this flat at Mira Road, Mumbai . We have requested society to waive off her unjustified interest accumulated in maintenance bill and wrote to them several times which society in last month declined our request. The matter is that, our society had carried out repairing and plastering work from unprofessional contractor in 2004, Which was faulty and there was heavy leakage to bedroom wall during monsoon the wall was getting deteriorated day by day. The space near wall cannot be usable due to the plaster fall. About faulty work we gave a written complaint to managing body of society, in reply to our letter committee assured that the work will be carried out soonest then . In letter we have also urged them hold certain payment of contractor until we satisfied but to our knowledge it was released by committee. The secretary and treasurer initiated repairing work have sold their flats and left this society within 2 years after above mentioned work. Further, society never bothered carried out repairing until May,10. We have verbally requested and written to society several times but they categorically avoided giving us any reply and nor carried out repairing. Hence , responding to attitude of managing body of society and their ignorance , avoidance and disregard to our request, in frustration we have stopped paying monthly dues after April 2006. It seems because it was the first instance that a member of society had lodged written such complaint to the society , which they expressed verbally when we met them and thus it sounded like managing body taking grudge on us and was categorically avoiding the repairing work. After the faulty work carried out there were total 4 managing bodies / committee formed but next two managing bodies also never bothered reply to our written request and attended repairing of faults. However , the balance sheets from 2005 till now is evident that they have spent /carried out other repairing works. Further , the elected managing committee in the year 2012-13 approached us and requested verbally pay off outstanding and in turn they would waive off our interest after reconciliation and assured that they would initiate patch work of leakage. Keeping trust in them we have paid around 80 % of outstanding on in Feb,2010 . and urged them via letter to adjust payment only against principle amount and requested them provide statement of account so that we can pay balance principle amount if any and also requested them waive off our accumulated interest part due to their avoidance and disregarding my complaint. But surprisingly after receiving our payment , this committee acted reluctant provide our account statement and eventually did not sticked to their verbal commitment waiving off accumulated Interest basically occurred due to their irresponsiveness. However, this committee had attended leakage repairing of our bedroom that is in mid 2010. When this body handed over to next elected managing body , we have once again requested secretary provide us account statement and instruct society accounts service provider issue us statement and upon receiving such letter from secretary , we have procured statement from year 2005 paying 500 /- to service provider and after reconciliation of same I had paid complete 100% of principle amount outstanding i.e. 13,925 /- in March ,13 along with a letter and annexure of accounts statement showing our computation and requested managing body waive off my interest part accumulated so far due to avoidance, and disregard of our complaint by various committees until then. This managing body also avoided answer to my correspondence and kept raising interest in my maintenance bill. Thereafter, we have regularly paid principle amount every month shown in maintenance bill excluding the interest part up till this month. We have once again made fresh effort in writing to present committee to waive off accumulated interest but in their reply committee mentioned that they will not be able to waive off interest and requested us pay off accumulated interest part soonest. The proper reason of refuting our request is also not mentioned in their letter. My mother is 79 year old pensioner of state govt. and hence society maintains pressure on her because may be they assume one day old age person will pay off interest playing tactics like non response to our request and avoidance , neglecting etc. In my limits I can only write letter on behalf of her to society committee but they had deliberately avoided respond to our request until a month ago as mentioned above. Kindly advise if there are any laws / ways to direct them waive off my interest and prevent them raise unethical Interest due to their non responsive attitude to our request and non attending my complaint ?? Thanks & regards K.Deepak