American Express Merchant Preauthorization

According to Consumer Act Section 75, American Express should not accept charges exceed credit line on any account. ( why still accept charges on a closed account )

American Express customer Service told me about this merchant has Pre-authorization upto 1 year to charge to my account, even though account close and regardless of exceed credit limit. Who gave the Pre-authorization ? What kind of Pre-authorization to allow merchant to unlimit charge to my account upto 1 year ?

According to Fair Credit Billing Act (FCBA), How American Express can get this kind of Pre-authorization to victimize consumer ? This merchant had charged to my account after account closed and amount exceed 3 times of credit limit. I had requested to close my account on 07/12/05 On 07/13/05, 'This account is currently cancelled', total credit line $4000 and available credit line $0.00 and outstanding balance $3932.40 appeared on my online banking. On 07/22/05, there are 3 charges to my account (1) $3000 (2) $3000 and (3) $685 My questions are (1) How these charges may go thru a closed account ? why American Express accepts charges on a cancelled account ? (2) 7/22/05 total charge $6685 exceed account credit line, what credit line set up for, if American Express accepts charges regardless credit line limit ? (3) Vonage charges $23 did not pass thru on 7/22/05, why some merchant may still charge but some can not ? (4) why American Express accepts charges to a closed account AND for how long American Express may stop accept any charges for a closed account ?

Please explain.

Creditcard.org's OPINION: We recommend possibly disputing the merchant's right to charge your card. Did you terminate the agreement with the merchant? Did you keep a copy of the letter?

Also, I have heard that American Express allows for merchant transactions to go through if they don't input a new dollar amount in the monthly preauthorization. They say it is for cardmember convenience but in your case it looks decidedly inconvenient.