Corporate screw-ups

I got screwed up by this Org, I hate this company for their pathetic service, They dont take care of the customers. These are some of the views that an agitated customer would have against some companies they deal with. 

Why do companies screw up on their services once the sale is made. I am talking about product related companies here. Have these organizations forgotten the fact that customers could help them prosper or totally ruin their operations by simple word-of-mouth opinions. 

How many of us jave gone ahead in a purchase decision after consulting with one's trusted circle? Though we dont trust opinions of an individual, we certainly consider those in the purchase decisions. 

Companies around the globe are concentrating on the "Customer delight" factor. Its a step further from the old adage "customer is king/queen". And we also see Organizations like Reliance, ABN Amro, Vodafone, Nokia focussing only on pushing their products and neglecting the part about customer service. 

I have written reviews about the attitude of these organizations towards customer service. And i have also received responses from these organizationds that they are "sorry for the trouble caused". 

My point or question here is - Should Organizations wait for their customers to tell them about their service or should they just pull up their socks and get theor act together?