HDFC Bank — Cash back not received

Address: Ludhiana

I have purchased i phone 11 on 26 november 2019 and they told that i will receive my cash back in approximately 120 days and it’s been more than 180 days and i have still not received my 6000 cash back.. I have written 9 mails in this 6 months but no solution.. They mailed me and said that they have put the amount on 26 feb or 26 march and told me to send the bank statement from 1 feb till date.. I attach my account statement which showed no entry of cash back and mailed them.. And now they r saying to send the bank account statement from the time of purchase.. How could they r not sure at what date they have accounted the cash back.. These r only the rubbish and crap.. This hdfc bank is total fraud cheater corrupt people...