You don't. I have been in the same boat - I've tried emailing firstname.lastname@example.org
, creating tickets online, calling, and even tweeting to @LastPassHelp and @LastPass. I have not received a single response. Not even an automated notification that they have received my support requests.
I have been a customer for nearly 10 years, and have gotten two previous employers to adopt LastPass Enterprise. I am an IT auditor and consultant and I used to recommend LastPass Enterprise to clients on a routine basis. I say used to because I just cancelled my upcoming auto-renewal because of the complete lack of customer support.
Fortunately, I was pleasantly surprised to find out how easy it is to migrate LastPass data to a free, open source password manager that hasn't been breached.