How do I add supporting documents as a buyer to a claim?

[Coser2]

I bought something and I got scammed. Seller actively says he will not ship but doesn't want to give me a refund either. He gave me a "oh well" kind of attitude. I want to upload those screenshot messages, but where to? I click every possible area on my raised claim resolution page but no upload button? All I see is paypal telling me that I have 0 things uploaded. Even though the seller was given 10 days to answer, and it's only 2 more days until his time is up, I still want to prove my side of the case in cold hard stone. I have been told that to wait it out and paypal should side with me as the buyer, but they also said there is a low chance they won't get me my refund. It's the holidays and I can't afford to lose a few hundred. I just really want to upload my proof to secure my claim even further and maybe have paypal process it faster. Please and thank you.

[sharpiemarker]

If you escalated the dispute to a claim, you cannot upload any documents as PayPal is reviewing the case unless PayPal is requesting additional info from you during their review.  However, you can contact customer service to speak with a dispute specialist to enable you to upload documents.

[rustratedme]

I tried to get customer service to do that yesterday, but the address I was given to send the supporting documents to wouldn't accept the email.I've been blocked from the website where she tells me to go to pickup my purchase, and here is one of 5 emails I sent before escalating the case.

[Whac-A-Mole]

if you file item not received and the seller does not respond or cannot come up with tracking which shows delivered,you win,no need to upload conversations.

just escalate to pAYPAL review when the time comes or if he does not respond in 10 days,case will close and money will come back to you 

[UtterRage]

My dispute isn't that simple. I disputed and escalated a claim. After MUCH wrangling (about 20 hours) with the store's customer service, I was promised a refund (again and again and again...). Now Paypal is reviewing the claim. Why? I want to submit copies of these chats with the store's customer service. The way this nightmare is going so far, if Paypal doesn't side with me, will I have any recourse?