If you connected the phone and used it in iTunes, then iTunes should have a record of the serial number and all that crap.
Find out where that is stored and provide them with that information.
You never indicated if you have the box with the serial number and IEMI number on it either, they should take that. What about your provider? do they have record of what you had activated on their network?
Otherwise I would suggest doing what I mentioned and calling Apple, stating you need to speak with Bill Frederick (VP of Apple Care) regarding a problem you are having with your Executive Level case. You will get his voicemail, and so leave him a message stating you are having issues with your case and wish to speak to someone else about it.
Find out where that is stored and provide them with that information.
You never indicated if you have the box with the serial number and IEMI number on it either, they should take that. What about your provider? do they have record of what you had activated on their network?
Otherwise I would suggest doing what I mentioned and calling Apple, stating you need to speak with Bill Frederick (VP of Apple Care) regarding a problem you are having with your Executive Level case. You will get his voicemail, and so leave him a message stating you are having issues with your case and wish to speak to someone else about it.