Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: Does not work

ITem is unable to create a vaccuum or seal plastic bags... customer service was surprised that I had bought it since I live at 7,500 feet, indicating that I needed special instructions which they sent by email. After buying a special screw driver with particular size star tip, and making the adjustments they said I needed to do, it still does not work. They said they would take it for repairs, but $25 for shipping across country is unacceptable. Avoid this unit.