Product: Money transfers

On XX/XX/2016, a woman ( the XXXX ) contacted me via phone. She wanted to buy a a high-precision survey instrument from me. The instrument costed over {$10000.00}. The XXXX provided me the information via phone. 
I used PayPal XXXX to process the transaction. Initially, the XXXX 's credit card was declined because there was a daily purchase limit on that card. I contacted the XXXX by phone immediately. The XXXX told me she would contact her credit card company to increase the limit. After about XXXX minutes, the XXXX called me to explain that she had spoken with her credit card company and resolved the problem. She asked me to go ahead and process her credit card. I tried to process the same credit card again, and I was able to successfully charge the XXXX. 
I shipped the instrument to the XXXX through XXXX ground service with signature required. The shipping address was the same as the credit card billing address. According to the tracking number record on XXXX website, the XXXX received the package and gave her signature in XXXX days later. 
But XXXX days after this transition, I received a notice from PayPal that XXXX filed an " Unauthorized Payment '' against me. Since then, I have tried to contact the XXXX by phone and email but have never received a response from the XXXX. 
After I received PayPal 's notice, I provided all the information to PayPal at that same day, including the XXXX tracking number, the receiver 's signature, and the detailed communication information between the Buyer and me, as well as the communication between the Buyer and her credit card bank. 
After XXXX months, PayPal provided me a notice : " We have reviewed the case. Because you have not met XXXX performance requirements, the transaction will be reversed. The case is now closed. '' I contacted PayPal customer support several times and asked for the name of the XXXX 's credit card bank so that I could directly communicate with that bank. PayPal told me that they could not provide me that information and recommended that I instead involve a relevant government agency or ask law enforcement to issue a subpoena. 
I have XXXX questions that need answers from PayPal and the XXXX 's credit card bank : XXXX. What are the details of the results from the investigation conducted by XXXX 's credit card bank and Paypal? ( e.g. Did the name not match? Did the address not match? etc. ) XXXX. Why did the XXXX 's credit card bank conclude that this was an " unauthorized payment, '' despite the fact that we provided information such as the XXXX shipping records and the buyer 's signature? 
XXXX. Did the XXXX 's credit card bank check the transition day phone conversation voice records with the XXXX? 
XXXX. The first attempt to process the credit card was n't approved because the charged amount exceeded the daily purchase limit. However, after the XXXX spoke with her bank and received approval to raise the daily purchase limit, the second attempt to process the credit card transaction worked. Why did the XXXX 's credit card bank conclude this was an unauthorized payment, despite the fact that the XXXX 's credit card bank gave the approval to raise the daily purchase limit on the transition day?