Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Battery charger

I recieved the charger however the charger doesn't work but I am able to use the power cord with my old charger which does work. There were no instructions with the unit which leads me to believe that the package may have been tampered with. Your site leaves my no recourse to return or address a complaint so I am using this source to express my dissatisfaction. Please advise as how to obtain a refund. Thanks!