I had bad service at a burger king location in new castle delaware ( long wait in drive thru- 45 minutes, since not enough workers to open inside sales ) so i took the survey, wrote the code number down on my receipt. a few weeks later i drove to burger king location in middletown, de for my free whopper with purchase. placed my order and handed receipt with code number to cashier. they told me that i had to have an app on my phone ? they didn't know what the code number was on the receipt. after trying a few times explaining about the survey code. walked out empty handed. not happy at all with last two visits at burger king, guess i'll have to find a different burger to start liking.