Instruction: Given the user's review, identify the user's sentiment from the listed options. Answer using one of the options.

Input:
I ordered this product and received it the end of February, 2012. I filled it per instructions using a ruler to be sure it was not over inflated. After setting it up, I kept it in a cool room.  Two months later I walked in the room and it was deflated and had come apart from the frame on one side. We have these items at our gym and I've never seen one pull apart so wondering if this one was defective. I called the manufacturer and they told me I had to deal with Amazon directly. I sent it back to the Amazon address provided, received a response plus a refund.

Options:
A: very positive
B: positive
C: neutral
D: negative
E: very negative
Answer: D: negative