Morestore — Refused to help in awaling the offer

I wanted to awale the offer as I received a message on WhatsApp about it. However the representative in more supermarket of Rajajinagar branch refused to give the offer. When asked they said it's for regular customers. I have been a regular customers to more for more than an year now.(this happened today- October 30, 2022)
On October 23, 2022 the representative didn't give the offer as she had already generated the bill and asked me to come next time before 31st October to get the offer.
I want to awale the offer and I can't do so then I would like to take this complaint further more.