Citibank Credit Card Complaint

Citibank Credit card department,

Billing disputes Virginia

In - I purchased an item online using my Citibank Mastercard. The seller did not have the item in inventory at the time of purchase but told me they would within a month. Two months later I still did not have the item and so filed a dispute on the charge with Citibank and they provided me with a conditional credit. The item then arrived a week later. When I authroized Citibank to reinstate the charge they charged me twice for the item. In several email and telephone contacts with them I was repeatedly assured the duplicate charge would be reversed yet they have not done so and I feel I have nowhere else to turn.