The person you spoke to was rude or unprofessional
You're forced to go through repetitive or irrelevant steps to get help
The self-service system was difficult or impossible to use
The quality of the service is inconsistent, and you never know if you will get good or bad service
The person you spoke to was incompetent, or wasn't trained properly
The company refused to admit making a mistake, even when there's obviously a problem
You had to wait too long to talk to a person
When you have to call more than once for the same problem, you have to start over from the beginning each time. The company doesn't keep good enough records of your earlier calls.
The person you spoke to didn't have the authority to help you
The company made it difficult to find the right options to be transferred to a person
The customer service representative won't transfer you to a supervisor when asked
The company doesn't do things it promised to do, like fix a problem, issue a credit, follow up with you, etc.