I’m afraid nobody in senior management will return your e-mails either, not least because most senior airline managers receive their e-mails via their PA’s for that very reason. All that would happen is that the PA would forward it on to the customer servcie department. I know a number of airline execs who don’t even have a visible e-mail address, their return e-mail addy’s just go straight back to their PA’s.
One exception to the rule may be Rob Fyfe of Air NZ! He regularly reads customers emails and replies to them personally.