Buyer disputed a payment alleging "unauthorized transaction" but how do I rebut?

[limerent]

I have reason to believe that buyer merely changed mind about the purchase. In order to resolve the claim within 7 days, I have 3 choices:

How would you like to resolve this issue?

Provide Shipping Information.

I have not shipped the item and I will refund the payment.

I have refunded the payment for this transaction.

None of these is the case. I have not shipped and I have no intention of refunding the payment at this time. There is no field in any of these choices where I can provide a narrative of what happened or upload evidence within the 7 days allowed. Why?

[limerent]

I had to wait for business hours to call Paypal by phone. Resolution Center rep tells me that there should have been a 4th option where I can provide my narrative. He said it probably was missing because they wanted me to call in and confirm that I haven't shipped the item yet. Weird. But anyway, they took notes by phone, which served as my response to the buyer's claim. Now they have to get the buyer's rebuttal.

[limerent]

Claim was closed by Paypal yesterday afternoon, in my favor. An hour later, buyer files another Paypal claim alleging "Item Not Received."

I was determined to ship the item, until today, when I weighed my options and decided to refund, close the transaction, block the buyer, leave negative feedback, and report the buyer to both Paypal and eBay.

Paypal and eBay were both very solicitous over the phone, which led me to suspect that this person's buy and cancel habits are not unknown to them.

There really should be a way for offenses like this to be more visible. The negative feedback I left was merely in text but had to be under "Positive" feedback, since it is eBay policy to not be abe to leave Negative or Neutral feedback for buyers. I really do not agree with this at all.

At worst, eBay buying and Paypal transacting privileges will be revoked for a period of time. I wish there were stronger penalties for this sort of thing. I feel the same way for Unpaid Item cases. But, oh well.

Paypal and eBay Community resources were most helpful. Thank you all for taking the time to post your expertise!