The customer may well be always right but the question to ask is:
Do you have the right customer?
Most businesses operate on acquiring quantity of customers over quality of customers.
Thinking that a customer is a customer and any customer is as good as another is misguided thinking.
One sure way for your business to go down is to spend your budget on acquiring large numbers of low quality customers.
And as these low quality customers come in you are suckered in to spending more to get more customers to make your return on investment work.
But if the customer is only interested in the bargain you are offering rather than the quality you are delivering, they will depart as soon as they have the bargain - and they will not value your offering either.
If you are in the business of offering bargains and it works for you, then fine.
But a good sustainable business demands high margins to grow and invest.
High quality and returning customers will always deliver more than poor quality and bargain hunters.