Flipkart — Regarding exchange of mobile phone

I tried to exchange the mobile that has minor body crack and other than that there is no damages or any issues. But Flipkart wish master rejected my exchange order and said this is not fulfilled terms and conditions. I think they need fresh mobile with low price. I don’t know why Flipkart says something on their site and cheating customer by fake promises. I am not sure the problem is with wish master or Flipkart.