Jumbo mobiles madurai - Not responding after receiving payment

I have approached Jumbo mobiles through Instagram. First I paid Rs.***** on ** Jan ** for One Plus **. Then Abhishek (Jumbo mobiles owner) said that the phone is not available and I can choose another phone (Google Pixel * Pro XL or Samsung S** Ultra) but the price was more ( Rs. *****) so I paid Rs. **** extra on ** Jan ** for Google Pixel * Pro XL. Then he stopped replying or responding to my calls. I kept calling and texting him.
Then on ** Feb **, he texted that even Google Pixel is not available and offered One Plus ** but I have to pay Rs **** extra for it. Then on ** Feb **, I paid Rs **** for One Plus **. By now the total amount paid by me was *****. Again, he ghosted me and stopped responding. I called him hundreds of times.
Then again on ** May **, he texted that this time he'll surely deliver it. The delivery charges will be extra Rs. ***. I paid Rs. *** extra hoping this time he'll deliver my phone but to no luck, he again vanished after the payment. By now, I had paid Rs. *****. I tried texting him on Instagram, commenting on his posts but nothing worked. I kept calling him and he blocked my number on ** Mar **. Finally I had to text him from my father's number on ** Apr **. He responded immediately. I even asked him about One Plus ** and he said that it is available. My father called him from his number and he picked up immediately and when confronted about my issue, he acted strange as if he is not aware. He was told to unblock my number and text me on WhatsApp which he did and said that he'll resolve the issue within ** min. But again, he has stopped responding and continuously cutting my calls. Even my father called but same again. No reply. No response. Such a fraud. Kindly resolve this issue.