Looking into class action lawsuit against COX for service install fees
The first place you should look is the TOS you agreed to but apparently didn't read. Then, if the tech gave you any paperwork detailing the problem he found and the remedy he performed, get the ticket number or whatever it is they call it, and call customer service again so they can read it for themselves and they should issue a credit. Or email cox.help@cox.com explain the situation in a much condensed form including the number and they can look into it at their leisure. They usually end up doing the right thing after they've tried everything else.
Where do the replays go? Why did my post from last week get deleted? What's up Cox?
