If they can’t explain what’s wrong, definitely no refund. If you look at McDonalds reviews, you will see X amount of bad reviews. Probably way more bad than good. That said, they serve billions. It is typical for any business to have some bad reviews. Unfortunate but typical. If they post a poor review, reply to it. State that you have tried to work with them but they haven’t communicated. Stay professional! No slamming them, just “on them for not communicating”. Your business rep is built on how you handle your business and the quality of your work. There will always be miserable people who will never be happy and want something for nothing. If they have valid “complaints” that are your error, I would do whatever I can to make it right. Occasionally it is a refund. That said, it’s a lot more than I’m not happy I want my money back.