Zingoy — i didn't get my cashback of 399... which zingoy promised at time of shopping with coolwinks

Fraud and worst app... No phone number to contact.. No reply from customer support mail... Many mails many complaints... But not a single reply... From customer care... I shop on coolwinks on 14 june... Zingoy promised to give 399... It also tracked... Maximum time was 90 days.. That is also over... Instead of confirming... They rejected it... I mailed them screenshot of successful transaction and order... But no reply... Very worst and pathetic service