I would say use the same thread. That way, if 3A's CS ever DOES pull it's head out, all the info they need on their own mediocrity will be in this one nice, tidy place. That's just my opinion.
I'm in the same boat, though. I haven't given up, but I'm so sick of being ignored. The last e-mail I showed you guys was the one in which they tried to tell me my figure is an isolated incident. They also told me they were going to be in touch with the admin of their FB page and would reply to me "very soon" (or whatever exact language they used). I waited a little over a week for that reply and still got nothing - still blocked from their FB. So I sent them another e-mail, a little under a week ago now, telling them how disgusted I am with their horrible customer service, how I can't believe they're trying to tell me that my figure was an isolated case when I literally have documented evidence of others experiencing this, etc. I asked to talk to one of their superiors; I told them I appreciated that they were being respectful to me, but still hated how horrible they were being at their job. And I didn't just say that as an insult - I told them that they're failing to meet some pretty basic customer service principles - those being honesty, urgency, and helpfulness. I just told them how dissatisfied I was that they continue to lie to me, continue to take weeks to respond with just a few brief, placating sentences, and continue to categorically NOT be helpful in this situation.
Yeah, that one was almost a week ago and I still haven't heard anything back. If I don't by tomorrow, I'm going to send them another one. I will keep sending them e-mails until they at least acknowledge what I want them to acknowledge.