I can corroborate Kathleen Grace: if you don’t hear back on an appeal within two weeks, it has been rejected.
Of course, I disagree radically with her about whether non-response is constructive customer service, or whether a one-line “you have violated BNBR” really helps you work out what the hell just happened in your 6 para answer. But there you go.
I have had two Spam notices and two benburrs (h/t Gigi J Wolf) within a month in December, after 15 months with no action. The Spam notices were both appealed successfully. Interestingly, one of the Spam notices must have been mislabelled; I didn’t even remember what the comment was, and on seeing it it seems to have been… BNBR against a former prime minister. Or ISIS.
The two BNBR appeals (one of which I’ve posted about at The Insurgency) have been unanswered, so presumed rejected.