hoarding contract by coop housing society

we are a coop housing society based in Mumbai. we had entered into a hoarding contract with an agency for 9 years. now in August 2014 the agency abruptly terminated the contract. without any reason. thereby putting the Society in financial loss. after terminating the contract the hoarding was never removed from our premises. but we got an offer from another agency and we were negotiating with them for transfer so that we are not put to loss. the deal fell through because the BMC refused to approve the transfer stating that since our society is about 30 years old no hoarding can be permitted on the terrace. BMC then forced us to remove the hoarding at our cost from the terrace since license had already expired and the agency also had defaulted on the license fees payable to BMC. we removed the hoarding at our cost now the agency wakes up and accuses us of causing loss to them and demands compensation and expects us to pay the license fees to BMC along with refund of the security deposit paid by the agency. now according to us nothing is payable to them but agency has to pay us for rent and reimburse us cost incurred by us to remove the hoarding. please advise us if our stand is correct and what should we do if agency takes legal action against us.