Are there any instances where a customer might be wrong?

Yes there are.
Many, and usually because of misunderstandings or wrong assumptions.
Happened to me.

Sure ! a customer could and can be wrong, " customers are human-beings" but the customer service general rule of thumb says " Customers are right even when they are wrong".
Each customer must be valued and satisfied.
Its more important to know how to deal with the situation and make a complete turn around while the customer is still satisfied.

Yes so many times it happened.but a good customer service officer handle him intelligently, without bothering the customer.

Of course (directly or indirectly), they're human beings after all :) Customers may be misinformed or haven't read the instructions properly or been misguided in most cases.
This is why there exist conflicts most of the time.
The same goes for companies.

Customers cannot be wrong mostly,although at some instances they tend to be faulty.From the side of the company we shouldn't look into it as a wrong thing.we should think him as a different type of customer who has different requirement from our product.When misunderstandings happen at the customer side,we should be clear that we have to make our product more clear to such customers in the future.

Why of course.
The mantra for organizations who place customers at the center of operations is "The customer is always right".
That is to say a dissastisfied customer is10 times likely to spread negative news about your business.
Your job is to try your best with in reason to increase customer satisfaction.
Notice I said with in reason.
To a certain point the customer is always right regardless if they are wrong.
There is a line and you must know where that line is regarding the interest of your company.

Yes, of course they are many times the customer is wrong but the rule state that "the customer is always right even when he/she is wrong" You just make sure the customer is happy ( That way the customer stays right).

Customer is a king, he can't be wrong.
his thrust for getting more satisfied guides us toward "opportunity" to think more and more forward to improve our product and services which obviously pay back .

Often, customers tend to be keen as always for both the item and the vendor.
They can see beyond just the product itself, they maybe either right or wrong but in the end, it's their right to inquire and assert being the end users.
However, this does not mean that customers are always right, although as vendors we must convey nicely all the messages we want to impart for them to understand every aspect we are trying to point out in such a manner not offensive to senses.
Instead of arguing, listen, show empathy let him/her talk & talk and for sure half of the problem will be solved after.
Then it's your turn to lay those cards to a tired person who is now willing to listen,he/she will grab it, you saved an additional income.

Yes due to a multiple of reasons and this is the role of the sales before the sale is done and customer service before and after the sale is done