Stamps1962,
I don't know the seller personally, but as a full-time credit card merchant for 20+ years and a corporate banker before that (specializing in global payments) I think I know what happened and it appears to be a misunderstanding by both buyer & seller.
Stateside card issuers are very risk-averse to "Cardholder Not Present" transactions as the rate of fraud is much higher than Cardholder Present (and why I have to pay a much higher fee for CNP transactions) as there is no chip, PIN, swipe or signature involved.
If you didn't "pre-advise" your card issuer and hadn't used your card with that seller previously your card issuer will temporarily block that transaction (technically "Refer to Cardholder"). If you're using one of the main issuers ie Bank of America, Citi, Chase etc you can set up an alert via cell text, automated call, or email to ask for your permission to proceed. You would then advise the seller and resubmit the transaction which would then be authorized.
The seller has to worry about card fraud – if he has too many declined or disputed transactions, he can have his merchant account (and even his bank account) closed.
You mentioned that seller didn't reply within 24 hours – many full-time dealers don't work on weekends and as France is EST + 6 hours, that might explain the lack of immediate response.
Also noticed on his website that he accepts PayPal for non-European buyers without additional fees – this would have avoided the problems with this transaction and is a generous offer as he'll get charged 5-7% from PayPal in transaction & currency fees. Very rare for European dealers not to charge a fee for using PayPal.
Steve Taylor
www.stephentaylor.co.ukp.s. he has been a dealer member of the APS in good-standing since 2000:
https://stamps.org/collect/detail-p...name/dealers