Mediacom Cable Mediacom wrecks customers computers, alters security certificates of other websites, does not return calls Springfield, Missouri

I was working on my website one morning and mediacom disconnected my service do to a bill being late, which was my fault.  I payed the bill the next morning and went to work on my website again and found that mediacom had replaced the Server security certificates of several of the websites that I frequent with the security certificate for their mediacom maestro server, which prevented me from accessing those sites do to the fact that the security certificates no longer matched. 
I called mediacom customer service and explained the issue I was having.  At first, the agent said I was confused and what had happened was not possible, he attempted to hold that line until I read him the mediacom security certificate that was coming up for the godaddy website.  At this point, he explained that I would have to go into my browsers security settings and manually remove the certificate myself and that he could not tell me how to do that, I would need to just google it.  I asked to speak to a supervisor and the man refused.
I hung up on him and called back at which point I was transferred to retention.  The man I talked to this time took down my information and and apologized and said someone would contact me within 48 hours.  72 hours later, when no one had contacted me, I went onto their website and filed a formal complaint.  I was given a automated response that said someone would contact me within 24 hours. 
48 hours after that when I called back in again, The agent again began to tell me that  was imagining things, at  which point I asked to speak to a supervisor.  This time after arguing with me for about 5 minutes, the man put me on hold for 5 minutes more and I did get to speak to a supervisor.  The supervisor informed me that mediacom does not support firefox (the most popular web browser people use) and that I was SOL. 
So now mediacom has screwed up my computer and there is nothing they will do to fix it.