You did not get a reply because we simply ignore support requests where users forget or don't save their private keys, this was the general consensus when we had the same issue a few weeks ago.
My opinion is that you should still reply to his support emails, and write him at least one simple explanation, this can even be general reply email.
Keeping quiet and not replying anything is not a good idea, unless you receive obvious spam messages.
He has letter of guarantee so he deserves some answer.