Instruct: Classify a given review into positive or negative sentiment.
Query: Disappointing SmartPhone

I had to return my BlackJack to AT&T warranty center three times! It froze a lot even though I frequently stopped programs using the task manager. I also reset it several times, but it never stopped freezing. The volume is too low, and I missed calls. Even at the highest volume setting, it's difficult to hear. The phone also becomes very hot when you are holding the handset to your ear. It's best to use the bluetooth device. I was very disappointed with the phone. At&T replaced my phone with a Blackberry Pearl.