Instruct: Classify a given Amazon review into positive or negative sentiment.
Query: Amp didn't work

I received this amplifier, and it didn't work right out of the box.I hooked up the 12v power supply, and .....nothing.I waited too long and can no longer return it.I didn't receive the follow-up email until AFTER my 30 day return policy was over.That sucks. That is comepletely unhelpful customer service.