Product: Credit card

My Chase XXXX card was duplicated charge due to investigation error for the dispute. 
The dispute for the charge was initiated on XX/XX/XXXX since merchant did n't ship my order placed on XX/XX/XXXX on his promised shipping date. So this charge is invalid. 
However Chase investigation was extended to the activities after XX/XX/XXXX. Chase only took into account that merchant has shipped his product on XX/XX/XXXX, but ignored the fact that I had made payment for this purchase on the same day. 
About XXXX billing cycles passed since the dispute, I did n't heard anything from Chase about dispute. on XX/XX/XXXX Chase sent a letter and stated that the charge on XX/XX/XXXX is valid. 
I was asked whether to continue to dispute this charge, I submitted documents to prove that I paid for my purchase. On XX/XX/XXXX, the card service department person still argued that I should pay for my XXXX purchase. There is no such thing as XXXX purchase. I only made purchase once and had made payment, which is well documented. 
The duplicated charge on my card is the result of unfair investigation. It is not the result as Chase card services explained as " merchant processed duplicate transactions ''. Chase creditor should not transfer XXXX charge into my account. 
Chronological record of dispute and transection:1. XX/XX/XXXX XXXX charged me {$3600.00} XXXX and promised to ship my order by XXXX. XX/XX/XXXX XXXX had no word regarding to my ordering status, and my monthly payment due date was approaching XXXX XX/XX/XXXX XXXX, I sent emails and made calls, did n't get replying from him. 
3. XX/XX/XXXX : XXXX replied and promised to send tracking number " tomorrow '' which was supposed to be XXXX. XX/XX/XXXX : XXXX still could n't give the tracking number, which was one day before my payment due date, I asked for the dispute over the charge made on XX/XX/XXXX. Bank temporarily removed {$3600.00} from his account. At this point the charge is invalid since merchant did ship his merchandise to me. 
5. XX/XX/XXXX : XXXX emailed tracking number, I made online payment for my purchase {$3600.00} XXXX XXXX ). He acknowledged that he received payment. 
6. XX/XX/XXXX : before receiving my online paymentXXXX requested credit since the disputed funds was removed from his account. I authorized his charge {$3500.00} & {$180.00}, which reected total owed.for the merchandise {$3600.00} XXXX XXXX ). 
7. XX/XX/XXXX XXXX realized that he charged me twice and performed refund on one of my payments, which is documented in his bank statement. 
8. XX/XX/XXXX : my card balance is XXXX, which means I paid for my purchase, XXXX received payment and refunded his duplicated charges. 
9. XX/XX/XXXX : Chase sent a letter and indicated that disputed amount will be in my next billing statement. 
10. XX/XX/XXXX : I faxed back a letter indicated I wish to continue to dispute this charge, associated with the proof that I had paid to XXXX on XX/XX/XXXX after receiving the tracking number. 
11. XX/XX/XXXX : billing statement showed {$3600.00} charge on my credit card12. XX/XX/XXXX : a letter from Chase states " we understand that you are asserting that merchant processed duplicate transactions and the merchant has promised to credit. '' This is a misleading statement. Merchant did processed duplicate transactions, however merchant did credit to his duplicated charge back to my account on XX/XX/XXXX. The duplicated charge is from the release of the temporary credit by Chase back to the merchant. 
13. XX/XX/XXXX in Chase branch, through phone talked to card service department person, who insisted that I purchased twice and that is why I was charged XXXX. This is totally baseless. 
14. XX/XX/XXXX,XXXXXX/XX/XXXX : discussed with card service executive XXXX She said Chase lost dispute to XXXX XXXX, that why the charge is on my account, which is unreasonable answer.