Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Disappointed, but was promised a replacement

The amplifier and battery arrived quickly. The battery was new and strong; however, the amplifier did not work. The only time I could get any discernable audio to the telephone handset was when the amplifier volume was at its lowest setting. At all other settings the audio was completely cut-off. The shipper sent a postage-paid return label and I'm hoping to receive soon the replacement amplifier. The instructions are very comprehensive and detailed. One week after the shipper received the returned amplifier I am waiting for the replacement to arrive.