Happi Mobiles - Cash back not received

Hello I'm Digamber who has visited Happi mobile store at Attapur, on Wednesday I.E. on *th of this month . We meet sales executive named with Mirza Altaf , and I said him I want Iphone ** pro ***gb , he helped me and explain me about price . Its base was Rs.*,**,*** we are offering you for RS. *,**,** , and plus Rs **** cash Back . He explained me about the offers slabs, in which I was having RS,***** cash. So the rest amount * lakh he asked me to divide in * parts as rs ***** pay from Amazon pay and Rs,***** from icici credit card to gain the benefits of cash back of each ****., In total rs **** benefit.. But unfortunately that day I can't make payment because of my card issue. So I was busy in some work I have send my friend to make purchase on Sunday on **th of this month . Sales executive( Mirza altaf) called me and asked my Amazon pay used user id and password to make payment . So I have shared him my account details so he can make payment. But they refused it after purchased saying that we won't give that cash back to you. Without my concern the sales executive have used my Amazon pay and benefits. which is unprofessional and bad experience for me in Happi mobiles . Hope I get my benefits.