Refund of security deposit from the landlord

Hi, I vacated my commercial premises after informing the landlord well in advance and had documented the same through messages about me vacating the premises. I also found another tenant for him so that there is no gap in the cycle and he can continue to earn rent from his property as I had to shut down my business. He now has this tenant using the premises. It has been more than 20 days that I vacated the premises cleared all the dues and now he is coming back with requests like you need to write to me on the contract copy that you have nothing to do with the rented premises and I will deduct the money for washroom repair work and putting window glasses in the office - this is despite the fact that I completed 11 months on the property. He doesn't answer to our calls and messages and when we call from a different number he responds. He has been saying that I am out of Delhi. I am a senior citizen and had to shut down my business because of constant losses in the business. I cannot afford to lose this money. What actions can I take here?