Definition: In this task, you're given reviews from Amazon's products. Your task is to generate the Summary of the review.
Input: I am not happy with this product at all they don't work when using them for call purposes the other person on the other end cannot hear or understand me. it sounds like a robot is talking. This is one of the worst products I have bought on Amazon ever.

I am not happy with this product at all they don't work when ...