Zivame — Refund related

I had ordered bra which i had to return because its cup was deformed. I paid 971 rs and 177 using jiocash,
They are giving me 971 refund in zivcoins but they are refusing to refund the jiocashback which i used. They say i have to read the terms and conditions but as per the terms and condition i should get the refund of jiocash in my jiomart cashback wallet. Nothing is mentioned on the zivame website and even in the terms and conditons related to this and also the when i asked the team to share me where in the terms and conditions is it mentioned, they refuse to tell me, please help me related to this.