Not sure if that's still the case, but a while ago as an AWS customer with premium support you got a very extensive list of phone numbers of AWS representatives to escalate issues to in case your technical account manager or his supervisor were not available in emergencies. While I believe the list didn't include somebody from AWS' C-level, it went pretty high up. As I customer that felt very good, because it gave us the confidence that there is always somebody available in case of emergencies.