When you go out for a meal and it is cold when it arrives, do you complain?
If you buy a dress and it has a stain on it, do you take it back?
Rather than calling these sort of things complaints, we should call them constructive criticism.
If you don't tell the restaurant that the meal is cold or that the chicken is undercooked, how can they be expected to learn from their mistakes.
If you don't tell the shop that the clothing is stained, how can they be expected to realize that there is a problem with their stock.
Sometimes we feel awkward when we complain, as though we should somehow feel guilty for somebody's mistake.
If we look upon it as constructive criticism, then maybe it would be easier to complain effectively.
By looking at it this way, we are also more likely to put our point across in a calm, concise way, rather than going in with all guns blazing.
Complain constructively, make things happen, improve your world.