garage charges

I am an owner of a flat with registered agreement of flat + one enclosed garage. I have been issued valid share certificate of the flat only without mentioning anything about garage. Society is charging from beginning in it's maintenence bill Rs 300 on monthly basis as garage charges. which is being paid in total till date. Now, after ownership of flat and garage for almost 45 years, suddenly a member posed a question why are we not charging water charges and other maintenence charges on garage with retrospective effect of 45 years. Society has not issued me any share certificate of garage. Society is thinking on implementing the idea to levy charges of past 45 years. My question is 1. is it legally possible to charge for past 45 years? 2. no share certificate of garage yet can they consider as leviable unit? 3. Can they pass any such resolution to collect such charges of past 45 years? please reply.