My first item not as describe dispute.. Need advises

[bad_bad_gurl1]

I recently sold an jacket to US-NJ. Buyer received item on Dec 15, open a not as describe case on the 16th stating that it looks different on the listing photo, and demand a full refund + postage. 

As a seller, I am 100% sure that the jacket she got was the same item in the listing. But anyhow, I posted a message in the Ebay's resolution center explaining the best I could and I also ask her to refund the jacket for a refund. 

However, I have questions regarding her case details;

buyer stated it was a different jacket, but she told Ebay in the case's details that it was a fake?!  Why is that happening?

Also, what more actions can I do to happily resolve this situation? How should I response in the case once buyer response ?

Is there a spot where I can click return for a refund or do I have to type that out everything buyer response?

[bb_cool_stuff]

Had a person out east return a shirt, rarely happens, & she was promptly refunded including the return shipping.

Seems there was a small flaw underneath the size tag that was never noticed previously.

I now check underneath all size tags.

No big deal, my fault & she still left great feedback.