Pagdi shop dispute

Hi there , i have a shop in uttranchal on pagdi system for which i had payed ₹50,000 in the year 1992 and i dont have any receipt of the payment of pagdi. Initially The landlord had fixed a sum of ₹300 as monthly rent of the shop. Till now iam paying the rent without any payment receipt . Now actual problem starts from here , in 2010 the actual landlord got died and his sons started taking rent and suddenly they had started demanding 500₹ as rent of the shop and i started paying 500₹ to landlord without any payment receipt. now in 2015 landlord is not accepting the rent nd saying to pay 14lac to purchase the shop or else leave this shop. Iam in big confusion on what to do next , as i dont have 14lac to purchase the shop and landlord is forcing me to leave his shop. NOTE :The electricity connection is on my name. Plz tell me do i have some rights in my favour or i just have to leave that shop? Will they pay me a reasonable amount of money if i leave their shop?