Shopping. Whether you love it or hate it, there are certain courtesies that should be followed to ensure everyone has a respectful and polite experience.
Do not hold salespeople accountable for things outside of their control. If the dress you want is out of stock, or you can’t get a refund you think you deserve, ask to speak with a manger who will likely be able to best help you with your problem. Likewise if you aren’t being treated with respect by a salesperson or they aren’t helping you with something that is in their field of expertise, feel free to mention this a manager.