Being a customer, keep your voice low and keep the relationship intact. If the service is awful, change it. It doesn’t make sense to yell to your service provide when you want to keep the relationship moving.
Being a service provide, make sure you serve the customers irrespective of their lifetime value. Refund value should be less than 10 percent. Understand your customers and solve their burning problem every time. You might earn a customer for life time.
Sugar on your tongue and ice on your head helps you go long distance. Good luck.