Hmm, that's interesting. You'd think that if they value customers as we think they may, then they'd at least send you an automated reply, to verify that they've received your email.
Let us know if you do get any communication from Sinclair HQ. Not that I want to know the precise wording (although that would be nice to be nosey), but it's merely to see whether you get a round robin reply, or if it's a personal one specific to your email to them.
Mike