That is weird. Did they say what the problem was that the manufacture can help with? Did you want to troubleshoot here?
If so, start by posting your signal levels. You can find them at 192.168.0.1 > user:admin password:password(unless changed) > Connection > Cox Network. Either upload a screenshot to Imgur and post the link here or upload a screenshot directly. See instructions here for directly uploading a image. Basically you have to join the Internet forum using the link on Internet forum home page and then you get the option to insert a file.