Reliance Digital — Not received cashback

Address:

Reliance digital,Maithili Sygnate, next to BSEL Tech Park, opp. Vashi Railway Station, Mumbai, Maharashtra 400705

I had purchased an Iphone Xr 64gb from reliance digital vashi on date 28/12/2019. I was promised a 5000 cashback from hdfc bank + 3000 cashback from reliance digital on behalf of their year end sale as i opted for the no cost emi method. After 120 days i received the cashback of 5000 from apple india from hdfc offer but the 3000 cashback is still pending from reliance digital. I have called their customer care various times and registered complaints many times but still no progress. Then i decided to visit the store personally and then they told me the same thing to do that is to register a complaint and gave me some telephone numbers and said that the money will get refund in 5-7 days and if the money doesn't get refunded into the account contact those number. After 7 days i waited and got my bank statement and in that there was no such refund received and then i again tried to contact the customer and now no one is picking the call. It's been almost 2 months i am looking out for a solution but still no progress.