Land issue

Hi, I am Vijay Rao from Bangalore, we have land in my home town (Andhra Pradesh) and planned to sell it, So one of mediator approved us with the buyer. We informed him we will not do any agreement it has to direct sell. The mediator and buyer accepted and asked us our bank details to process the full payment. buyer transfer some amount and diamond to do agreement, we rejected the agreement. we are in touch with the mediator and asking when the remaining amount will be paid and do the registration. After 1.5 years they told after the Andhra Pradesh election will pay and register the property. after few days of the discussing the mediator called me and informed that the buyer is not will to buy the land, so I replied I will not refund the transfer amount to him, but the mediator is harassing me to pay the money to him and also approached to police and raised a complaint on us. The police officer is also supporting him and given us the deadline to refund the amount. Kindly help us how to proceed, I have all clear documents and recorded the mediator discussion had with us.