Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Very unhappy - Unresponsive Vendor

I ordered a book for my daughter's school in the first week in August. It did not come in the estimated time frame so I had to rush order the book from another source with additional shipping charges. I had concerns about when the book would come so I emailed weekly but did not receive a response to any emails. After three emails and a final request for cancellation of the order I have still not received any response or refund. I have filed a complaint with Amazon as well. I generally do not submit reviews but I think this is so unprofessional.I would stay away from this vendor.