I've run into a bit of a head-scratcher while integrating Amex credit card payments into my PHP script for Authorize Merchant Services. I'm facing is that the CVV (Card Verification Value) for Amex cards doesn't seem to be getting validated correctly. I've double-checked the code, and it seems to be in line with the API documentation provided by Authorize. The strange part is that the CVV validation works perfectly fine for Visa and Mastercard. Has anyone else faced a similar problem?
