Indian Army — cooler selling

Address:

near senapati bhavan, Ratanada, Jodhpur, Rajasthan, 342011

I uploaded an add regarding selling of a cooler on olx on 29.05.19
Few buyers called up
One was him
He called up and said that he would pay through online mode. I had no issues. He said he would the amount now and someone from his home will comw tomorrow and will take the cooler. I said fine. He sent me a link and said that he is paying through paytm card on phonepe account. I clicked on it and somehow from my account rs.1100 were sent to his account. Now how asked me for my paytm login and password and said that he would transfer money to my account through his paytm card. When i refused he said that he will not give me my money back until i send him my paytm id and password.