Problem with a purchase shown on your statement: Credit card

Dont have the exact dates handy but refer to chronological events : 1. Entered into a transaction with merchant but item was unavailable at the time but transaction using Amexvo was entered, thus a transaction slip 2. Went to Merchant to officially cancel said transaction and said that they will cancel. 3. Received billing from Amexco reflecting subject amount. 4. Opened dispute with Amexco on the grounds of non delivery/receipt and submitted pertinent documents. 5. Dispute was closed in favor of Merchant. 6.Filed reconsideration but to no avail