Has anyone faced a customer who had a problem with the product and you could not solve it? What did you do?

first of we need to make customer calm by listening thier issue with the product and need to appologiges for the problem they faced due to it,then we need to convience them to exchange the product with same quqlity and quantities if still they are unhappy we need to go through the company policy of returning cash or reporting to our line manager

Listen to them; make sure they understand that you hear their concern.  

Be empathetic and guarantee your product by offering them a full refund.

At times, (depending on the situation), you can offer a token gift for their troubles; such as a gift card for $25 to a popular retailer that does not compete with you. 

Do this sparingly as some might be taking advantage of the situation.   

Your question inspired me to write a blog on - How to solve difficult situations with customers regarding a problem with the product?

It is not poor performance if you don’t know how to fix the problem with the product, but, it is poor performance if you don’t know how to solve the situation with the customer!

See the full blog here:  https://www.bayt.com/en/specialties/b/16005/how-to-solve-difficult-situations-with-customers-regarding-a-problem-with-the-product/?first_p=1

i had such as problem and i solve it immediately by giving new product and to provide long term for waranty 

in such case you have to follow the rules , listen , understand and resond on the situation , in case no one can solve the problem must direct the customer to the right place where he can find someone knows about the product. for sure there is specailist for customer solving problems 

Yes I faced like this issue, but in the end of the story we find the good solution for the problem.by discussion with the costumer and my management.

most importantly, we shall keep in miind that custumors are kings. I think the best move is to smile to the custumor and listen carefully. After that calm him or her down and try to help them weather it is physically or just suggesting solutions and reporting the problem to the target manager, in a positive atmosphere of course. 

honestly, I faced this example like a thousand time, the most important thing you need to do in cases like that, 

1st apologize about whatever customer angry of 

2sec make the customer feel that you are totally sympathetic to his situation.

3rd show him that you totally in his line, and make him notice that you are doing all you can to do

if you did that main points above well, then you have officially solved the problem.

I make it a point that i know what exactly their complain and i assure them to give an solution and suggest them if they want other products and give the assurance that the quality of products is really good

FIRST OF ALL WE NEED TO ENTERTAIN HIS/HER CONCERN,KNOW WHAT EXACTLY CAUSES THE PROBLEM IN THE PRODUCT.,IF I CAN'T RESOLVE IT THAT WOULD BE MY TIME TO ASK HELP FROM MY SUPERVISOR OR ANYPERSON WHO IS ABLE TO ANSWER HIS/HER PROBLEM AT THE SAME TIME,LISTEN ...