Association recalculated maintenance fee for last 12 years

Hi, I have been living in an apartment in Bangalore for last 9 years and paying my maintenance fee regularly. Recently our association has given us an invoice claiming we have a large pending amount because they have been calculating maintenance fee for our flat using wrong area number for the last 12 years. We don't even know which area calculation they use and why they use the number they do. I have the following issues with this: - We have been living here for only 9 years, and at the time of moving in, association gave us no due certificate. Can they charge us for the time we were not even residents after they declared all claims are settled and gave no-due certificate 9 years ago at the time we moved in? - They are charging interest on the difference for between paid and newly calculated amount for 12 years. We always paid the amount they asked for in the invoice. We don't even know how they calculated and if they were making a mistake. Can they charge interest on difference in amount due to their own mistake? - How long back can associations go in recalculating and claiming differences? Can associations go as long back as 12 years to re-do calculations and levy additional fee and penalty?