I'm having a similar experience at the moment. Since I bought some stuff in the recent sale, I've stopped receiving any mails from their mailing list. I got a reply from them suggesting that I check spam folders etc. I replied apologising because I should have made it clear in my initial email that I'd checked that, and also checked for any accidental filters that had been created. Haven't had any more replies since, even after sending a follow-up mail.
It's frustrating. I'm an unlimited member, and I want to get their mails so I can give them money! I have to assume it's because of understaffing, so no shade at all to the staff on the front lines who I'm sure are doing their best. I've been in similar situations myself at previous employers. When faced with a thousand problems, you have to pick your battles, and I can see why mine would be very far down the list of priorities. Still, it's frustrating.
I suppose I could sign up on a different email address, but then I'd miss any unlimited exclusive mails like the sales codes.