Updating this to help with future inquiries
Vladimir is their US representative. He was not very quick about replying to emails, but he always got back to me, and he was good to deal with.
I had to pay shipping to send my sub to determine if the issue fell under warranty or user error. I made the mistake of asking my girlfriend to ship it for me, so it cost $107.
Deaf Bonce determined sub issue wasn't user error. Vladimir knew I had a matching pair of subs that are discontinued, so he offered me TWO new subs in their updated model.
New subs are going to be here next Tuesday (five days from now). Only caveat is that I send my second defective sub to them after I receive my new subs.
Subwoofers' issues: One sub had an open voicecoil. Deaf Bonce couldn't figure out why the voice coil opened. Both subs' baskets are cracking. These subs have iron baskets; replacement subs have aluminum. I honestly don't know which is better other than weight.