Phone pe - Cash back not given

I have purchased **gm of gold on *.**.** during Dhanteras promo period (**th Oct - *th Nov **) of Phone pe after thoroughly enquiring with their customer care, who have informed me that the **gm worth i.e ***** odd amount would be given as cash back on delivery of ** gm gold with in ** hrs of payment. With the above information and instructions I've purchased and deliver of ** gm gold( which is dispatched to my address as per available info) though it's been more than ** hrs I haven't received any cash back. When the same has been enquired with the customer care they simply say that your transaction is not applicable for the ***% cash back and they don't tell me why it's not applicable to my transaction and never they have told during my previous conversation (before purchase of gold) nor mentioned incondions their web site that the ***% cash back is only for some transactions. Hence I Request you to look in the matter as I would have not purchased gold online of they would have not told they would give ***%cash back please help us(* of my people) in getting ***%cash back(**gm gold worth value) . I've also got audio records of my conversation with Phone pe customer cares which will be provided as proof.

thank you