Customer Service did not make the changes they promised, then hung up on me

I have been trying to cancel my DSL for most of the afternoon because they were not able to give me the price for the service they promised me last month when I called about being overcharged. Not only did they refuse to credit my account as they had promised previously, but I just spent 45 minutes on hold and then got hung up on when I was trying to cancel my service. I am done with this company and will tell anyone who needs their services to stay away.