LG Electronics — Regarding graffiti coupon

I bought a LG tv through reliance digital website. There was offer on LG products that I will get rs 5000 giffiti coupan within 60 days. So I contacted LG customer regarding it and Ms Shamly Rai was assigned to look into my issue(after calling customer care multiple times). First I was told that I should have registered in the pre book offer before buying but I told them there was no mention of it on reliance website and I tried to call them but no one picked up the call during lockdown and later after I provided all the proof, Shamly Rai told me after taking my case that I need not to do anything and reliance digital will provide them the bill and my coupon will sent directly to me. It was told to me in july and it has been more than month and I haven't received any coupon. When I contacted her again, she told me again to contact the customer care. Please look into this.