Flipkart — Coupon not received as per terms

I ordered boat avaante 2000 soundbar. The installation was delayed by 1 week due to technical issue, the request for installation had not been entered at all, finally it got done after close to 30-40 support calls/escalations.

After that I didn't receive a coupon which is clearly mentioned in the offer list and terms and conditions. The offer clearly states if I'm a first time boat buyer on Flipkart i will receive a coupon to buy boat rockerz 355 for rs 1 on 5th May. No coupon received, again had 40-50 calls with escalations, everyone one agrees it is supposed to happen but no one has the authority to fix the issue. The resolution time now provided is beyond the offer period itself. Seniors who this issue is escalated also just queue another request without any solution.
In the past few months i have experienced the worst customer support response from Flipkart, causing me to waste days of my time following up and escalating with no avail, call drops, explaining the issue over and over again in each call, wrong responses, technical problems, etc.
This is a severe breach of consumer trust and there has to be action against Flipkart for doing this.