I suggest you email SVS to find out what the issues were. As far as I can tell SVS is known for their quality and reliability. I have 5 subs including 2 SVS ones, one is over 10 years old and gets used almost every day. If you email them about your situation they may let you buy direct from them. For the size of your room, and since you like punchy bass, you really can't go wrong with their sealed models such as the SB1000. You may also consider one of this
VTF-2 MK4 Subwoofer that apparently can also be run in sealed mode. At 64 lbs it is more costly to ship but for $599 even with shipping you should still be able to stay within your budget.