How do I file a complaint and escalate my issues with Verizon

I have had more than one issue with Verizon since I starting using their services less than a year ago. I had a nightmare at installation with their customer service reps and it seems like the nightmare is never-ending. I contacted them today in reference to services I removed from my account that I was still being billed for. Upon contact and going through the many automated prompts and waiting on HOLDI reached an associate who asked what could he help me with. As soon as I replied I was being incorrectly billed, he quickly told me to call back and HUNG UP ON ME! This is not the first time I have been hung up on from a rep. I called back immediately and reached a very nice rep who informed that there was no record of the call. Verizon needs to be held accountable for its associates actions. Their "customer service" is the WORST! Their should be a way to trace BAD customer service reps who hang up on customers!!!!