Product: Checking or savings account

My complaint concerns a claim ( Reference Number XXXX ) I filed with Citibank for unauthorized transactions on my account. I lost my Citibank MasterCard debit card sometime on or around XXXX without my knowledge. I discovered the debit card missing on XX/XX/XXXX when I was going to use the card for a transaction and couldn't locate the card. I immediately called Citibank customer service, and was transferred to the Fraud Department. I was asked when was the debit card lost, and I answered, " I don't know the exact date, but sometime around XX/XX/XXXX because that is when the unauthorized transactions began. I asked if there were any transactions on the account as I was concerned the debit card may have been compromised. I was informed there were six transactions on the account. I told the Fraud Department representative that those transactions weren't mine. I hadn't used the debit card since XX/XX/XXXX. The Fraud Department representative then transferred me to a dispute resolutions specialist in the Dispute Resolutions Department in order to file a claim. From the date the claim was filed I've received two letters from Citibank. The first letter, dated XX/XX/XXXX, stated an investigation had been opened for a transaction on XX/XX/XXXX at a XXXX XXXX XXXX for {$240.00}, and I received a provisional credit for that transaction. The second letter, dated XX/XX/XXXX, stated an investigation was opened for a transaction on XX/XX/XXXX at XXXX for {$71.00}, and a provisional credit was also provided for that transaction. I waited to receive correspondence for the remaining four unauthorized transactions that were filed in the dispute, but I didn't receive any additional letters. Accordingly, on the eleventh business day after I filed the claim ( XX/XX/XXXX ), I called the Fraud Department to ascertain the status of the claim. I explained what I just wrote. I received letters for two of the six transactions, and a provisional credit had been applied to the checking account for those two transactions. I wanted to know why I hadn't received information ( letters ) concerning the other four transactions that were suppose to be in the claim, and why I hadn't received a provisional credit for those transactions. I was told those four transactions are still pending in the Fraud Department. I then asked to speak to a supervisor about the claim. I explained to the supervisor that Regulation E as set down by the Federal Reserve System provides the rules and guidelines for EFT systems, which includes POS terminal transfers. I said in many cases, especially those similar to mine, banks have 10 business days to investigate a reported EFT error, at which time either the claim investigation must be completed, or a provisional credit provided. The supervisor ( XXXX ) said she would expedite the claim to another area within the Fraud Department, and that she would call me at XXXX XXXX on XX/XX/XXXX to provide an update on the claim. Today is XX/XX/XXXX, XXXX didn't call, and there hasn't been any additional provisional credits applied to my checking account. Citibank is violating Regulation E for my disputed debit card transactions. I've attached the two letters received from Citibank, and a copy of my account transaction history from XX/XX/XXXX through XX/XX/XXXX. I wrote, '' need credit '' next to the four transactions that need to be provisionally credited to the account.