Supplier took advance & not refunding money for imcomplete work

Hello All, I had made advance payment of INR 8000 on 1st May 2017 against total amount of INR 15500/- (as agreed & mentioned on Quotation) for decoration work for my commercial property. The supplier is a "verified supplier" from INDIAMART (A website that deals with suppliers).The supplier start their work (which was at my commercial site) on 5th May. Later on he did not come, I tried to contact him over phone, after many attempts, he sometimes pick my call and gave assurance of completing the unfinished jobs, but he did not. When I realise that the jobs were no longer required to me, finally I asked him to refund the balance amount , he agreed over phone and confirmed on mail several times that he will refund my money but he did not and gives another date. The final date was on 31st May 2017. But he too as usual, did not refund the same. I have the proof of advance payment which was made through online transfer, the hard copy of quotation, and his mails. Please suggest and help me how can I get the refund my money legally. Are these proofs are sufficient to take action on him... Kindly help! Regards, Kalyan Datta Kolkata