Refusal to return deposit amount by land lord

I have stayed as tenant in 3 BHK independent house for 12 years. There was an unregistered rental agreement for initial 11 months, with a clause for increment of rent @5% per annum. I had paid 10 months of rent as Security Deposit. However, after 4 years of stay, the land lord demanded additional security deposit. Since I had no money, we agreed upon that, (Orally) rent shall be increased by 10% per annum, thereby the additional increment of 5% shall be payment towards Security Deposit. Now that additional 5% had grown to 220000+ initial deposit of Rs.50000/-. Now I have shifted to a different house. However the land lord is not ready to give back my security deposit after deduction of customary repair charges, painting charges etc. which may work out to roughly about Rs.40,000/-.. He had to return back at leaset Rs.150000/- Lac. He says he never demanded additional deposit. Hence additional payment of rent shall not be considered as Security Deposit. What legal course of action can I take ? and what remedies are available under the law to recover my hard earned money?