Unless you signed a waiver of responsibility here is what I would do.
Find out exactly which capacitor was leaking. Email the manufacture describing the problem and the leak. Ask for an estimate for repair.
Send the amplifier to the manufacture and get an estimate for the repair of the catastrophic failure.
File a claim in your local Small Claims Court. Testify with both estimates and the verbal, "pretty much blew it up,," as well as the admission they plugged it in after they noticed the leak.
Detail all your costs such as shipping, travel, and time spent.
Your showing due diligence for a minor problem and they're returning you their failure.
Find out exactly which capacitor was leaking. Email the manufacture describing the problem and the leak. Ask for an estimate for repair.
Send the amplifier to the manufacture and get an estimate for the repair of the catastrophic failure.
File a claim in your local Small Claims Court. Testify with both estimates and the verbal, "pretty much blew it up,," as well as the admission they plugged it in after they noticed the leak.
Detail all your costs such as shipping, travel, and time spent.
Your showing due diligence for a minor problem and they're returning you their failure.