Bikayi Com - Dummy mobile send online fraud

Https://www.bikayi.com/MobifyStore
Purchased mobile from above online under order no. *****-*c Dated **-**-**** and recieved unit on **-**-**** from blue dart courier docket no. *********** on receiving order immediately reported matter to seller On whatsup no. ***** ***** and assured me it's send by mistake and refund/replacement initiated within ** hour as oder is COD paid inr ***** to courier via gpay. . But then on action done by seller within ** hour contacted seller many time but no response from seller . And also contacted bikayi.com officials they also denied to help as they told we only provide online platform to seller and no concern whether they are frauds or not. No responsibility of same.
I am cheated and want my money refunded.