Instruct: Classify the given review into positive or negative sentiment.
Query: The calculator did not work

The calculator did not work when I got it even after putting new batteries in it so I contacted Mr. Carlson. He was so nice and got right back with me. He apoligized for it not working and said that he would return my money. And in a few short days, I got a check in the mail from him. I found him to be a very nice guy and very true to his word.