After buying a bad product or paying for a really bad customer service, most of us don’t take measures to bring the issue to notice of concerned people. Even if we want to complain, we ignore it as just a waste of time and energy. Then we think of it as a bad experience and a lesson learned for future.
Every time you see a bad product or any such incidence, you may need to place a complaint. Unless you complain nothing is going to happen - and to make sure your complaint is as effective as possible, learn how to complain about a business or a service.