What did I do wrong?

My sister's statement today made me realised that absence of customer complaints do not indicate a customer's satisfaction or happiness towards a company's service. Recently, she was not able to pay her mobile phone bill on DiGi's website due to the website's technical glitch. (For some reasons, she seems eager to pay her bill early whereas most people would pay after the line is barred). 

I told her to call the helpline and lodge a complain. She said she is not bothered to make that effort (to call) because she thinks DiGi will not do anything about it. So why bother? Her thinking, rightly or wrongly, reminded me of Starbucks pledge, "Our Promise". The public display of "Our Promise" at the pick up counter gives assurance to the complainant that a solution is available and known. 

Well, I foresee her inconveniencing herself by driving to a DiGi shop to make payment.

My conversation with her made me realised (again) that a company needs to proactively seek feedback from customers. Reactive approach may cause a company to lose disgruntled yet silent customers. The best part is the company would not even know why customers are abandoning it.