Had to change this post as I realized I was giving you some bad advice. lol
Since the business has closed, its very unlikely they'll do anything to provide you with a replacement amp.
With that said, you could get on the waiting list for an amp/driver upgrade from Sandbagger for something around $700 or just say the heck with it and find another sub.
The problem with just buying an amp from parts express and hobbling together a way to make it work is that its possible that the driver is damaging the amp and after a short time the new amp will also fail.
Samsung 64F8500, Panasonic 65VT50, Oppo 95, Tivo Roamio for OTA, Dish VIP722, Marantz AV8801 preamp, Rotel Amps, Atlantic Tech 8200 speakers, Seaton Submersive HP, Calman 5, Chromapure, VideoForge HDMI II, i1Display3pro, i1pro2, eecolor colorbox.