BOGO Promo - No free item, no response from support

I purchased a buy one get one free deal today and I didn't get my free burger. Every time you update your app it is harder and harder to communicate with you. I have the slip as evidence and your support team has not "reached out" with a response yet, what is there to investigate guys??? Simply look at your invoice and the receipt I got from McDonald's. People didn't eat because of you, what's the point of the service if you keep getting worse. You are notorious for not responding and I hope u do in this case because I won't let this go! It's the principle! Fix it please!