Did survey off of receipt for Bogo bigzax snak meal

Did survey off of receipt for Bogo bigzax snak meal. Survey scan said it was good for the end of the next month after the date of the survey. Email date 8/8/26 went to redeem it 9/30/26. Cashier said it was expired. She called a supervisor and they said it was a screenshot and it was expired. It was not a screenshot. It was the scan that came with the email. I explained to her that it was good till the end of the next month she said no it was good for 30 days. I told her that was not what the email said. She stated that it was expired and it was a screenshot and she was not going to discount it. So I canceled the order and went to Slim‘s chicken to eat where I had a bogo. I was very disappointed in how this was handled. If it indeed expires after 30 days it should say that on the scan that is emailed to you. She said something about it being redeemed on the app. That has not been the case in the past when I used one. Either it needs to be explained on the scan that comes in the email so customers know when it expires and how to redeem or the employees need to know the redemption rules and expiration.