Swiggy - False offer and faulty application

When I opened swiggy app to order food online I saw there are offer showing up next to few selected restaurants. It says ** mins or free. So I selected McDonald's. I ordered my food around *:** pm and I receive my order around *:** pm. So I initiated a chat with swiggy. I provided all the information and screenshot. The agent said sorry for inconvenience but that offer is for few selected places. It's not valid for my area. I said if it is not valid than why I was getting that option next to the restaurant name that mean you guys are using faulty app. The agent didn't reply for couple of minutes. Than the agent replied stating that I should need to check the offer before placing request. I felt it was rude. I am not so dumb that without any offer I would start arguing with anyone. Than I ask the agent to arrange call from supervisor, he denied. Than I called customer support wasted my ** mins and ask for supervisor the agent said he will arrange a callback within ** mins from supervisor, and mentioned currently no supervisor available. I waited but no one called me. I even have the recording with me.. They didn't value my time. Can't manage faulty application. No care for customer. Horrible customer service and technical service.