What skills should a cutomer service representative should possess?

There are two very important Words here "customer" and "service."

Customer means that there is someone more important then yourself. It means you need to practice understanding and patience. The ability to stay calm and to calm others in the face of adversity. While many customers are satisfied, many are not. It's not about you.

Service - the desire to "serve" or provide a service to customers. Again, it's about putting the "customer" first.

After that, it's about the ability to communicate effectively both orally and in writing. You need to be able to be knowledgeable about whatever service you are providing.