TAKE.THE.MONEY
promo codes and vouchers are like mail in rebates. Such a high breakage percentage. Don't fall victim to that.
Get the $. Then you can choose how to spend it next time.
/props to Heathrow for passing out vouchers.
//Story time: Last month, a family member was in Rome for a 5 hr delayed AC flight. With a tour group of 67 people. They had no idea they were due compensation. Asked at the airport and there were no forms despite being required by EU law. Agent called headquarters who could only offer a % off coupon.
Fast forward a month and ALL 67 tour people got their ~$704 USD EU compensation checks in the mail. With a huge thank you to me in all further communication from the group leader. Not only that but I had told the group to use the 5hr delay to make friends and spread the word to all other passenger on the widebody aircraft. (If I were there I would have printed 400 copies of the claim info/template in the lounge and distributed it in the boarding line).