Olx India — took money from me on the name of payment and did not return

I posted an advertisement to sell ac and got a call that he wants my ac and will do payment from bhim upi.. I was new so was not. Aware of the pin thing. He told me to enter the pin to transfer the amount but then he didn't pay and took my 2k too. He s not receiving the call as he told me that he will send a guy to my place for ac and money. I want you to help me to get that guy. I am attaching the proof of payment.