Charter Communication promiced 15mps service of internet but service is not there.3ms Worcester, Massachusetts

I reported poor speed test results for my internet service and got the run around for about a week. A tech came out and replaced everything but my computer. He used his computer by passing my router and still got the same result. Poor speed on the internet. 3ms and below. 

I am paying for a 15ms service . The tech left and could not give me a time that this situation would be corrected. I called support and got the run around and unfulfilled promices. A tech was comming right out ! They will email me on what the problem is and what they are going to do about the error.

i did get a credit on my account allegedly. I continued to try to put something in writting to the company but got a chat line only. This reminded me of a ponsi scheme being bounced from one tech to another. No answers or correction was done on complaint. Refused to let me speak to a supervisor.

Right now I wonder how long I have been paying for a service that I paid for but did not recieve. I think the Attorney General for Massachusetts should look into this.  I am schooled and very familiar with computers , bandwidth etc.., .