What should I do in this situation? (Paypal issue!)

Okay, so here’s my story.

T-Mobile sent me a new phone by accident (it happens). Of course, I was billed for it. Because it was a new phone, I decided to sell on ebay for a slightly inflated price so I could pay back T-Mobile and make a profit.

I found someone who had an okay amount of seller feedback, all positive. She had a verified Paypal account and she bought the phone for its said price. She had emailed me some questions about the phone, but all was good, and she said she was happy with it. She left me positive feedback. That was in early September.

Come December, on the 26th exactly, she files a chargeback. She says that it was an unauthorized purchase, so she never paid for it, got it, etc.

I got really angry with the little tart. I sent all the emails, ebay messages, and the feedback she gave me to Paypal so they could reverse it. I know I’m in the right here.

(I know she was lying because she contacted me about the phone using her eBay, paid with Paypal account, AND her own email. She acknowledged receiving it too on the address that was on her paypal.)

Anyways, I get this notice back from Paypal. They’ve sided with me, but apparently too late because her credit card company got involved (didn’t hear MY side of the story) and gave her back the funds. My Paypal account is in the negative (I didn’t lose any actual money in this ordeal)...there is nothing I can do and nothing Paypal can do for me.

I want to just end my account there and get a new one. This woman scammed me and she knows it. I sent her an email and told her my side of the story and I told her that I KNOW she’s being fraudulent, but she didn’t respond.

No way in hell am I paying money for her bad deeds.
Any help here?