Instruct: Classify a given Amazon review into positive or negative sentiment.
Query: Review What ?????

I can not review the Lentek PD01C dog trainer that I ordered. I was sent a different type of dog trainer/repeller without contacting me. The unit I got doesn't even have a strap, is smaller, and doesn't work against barking dogs. This review is for Amazon.com. I am unhappy. I should have been contacted before I was sent a substitute. Now to send it back I have to pay shipping and a 20% re-stocking fee. So I have to spend more money for something I didn't order to get back part of my money. Amazon.com you suck.