I would contact the seller. I sent a package out on 11/22 that my customer ordered on 11/17 and we figured a few extra days would be needed due to the thanksgiving holiday. Today, we both agreed that it's likely lost so we are sending out a replacement package. So, it happens, unfortunately, but the seller may not even know. My customer and I have been in daily contact and are both very
at the post office!
Edited: just realized you contacted the seller - I'd contact again, by phone if possible.