I have found the support of cable and DSL ISP’s to be worthless anyway!
Just yesterday, a friend with a Mac and Comcast (cable) called me and said she has not been online for a week or more. She spent a couple hours online with support and they told her everything was OK on their end, but she would have to upgrade her mac OS or Hardware (10.2.8).
Of course, I told her this was bunk…...
Took me about 5 minutes over the phone to see that she had a valid IP and ethernet connection to the cable modem….....told her to remove and replace the DNS numbers in the mac sys prefs…....and, of course, it worked immediately!
I have had numerous instances of the cable companies DNS not working, so I have a bunch of public DNS servers listed on mine…..but for the tech to not consider this shows complete ineptitude! It should be one of the first things on the checklist…..like making sure the washing machine is plugged in!
Moral of the story…..always check and replace your DNS servers when things are slow or not working…..