I've found it's best to register and establish a more permanent relationship with a vendor so you don't have hassles.
For instance, a couple of times I tried to buy something from Macy's online (don't bother, waste of time). They at first accept my CC, put the order thru. Then it never processes and they never inform you or tell you why. When I inquired I was told my CC was rejected, they could not explain why, cause it works everywhere else. I did drag out of them that they use some third-party service to verify the CC, and if anything doesn't match this third-party's record the purchase is denied. This probably includes, other info besides the CC, like a phone # not matching or a street addy. No matter what I offered Macy's including sending them pics of my CC, they would not put the sale thru...
So I understand the onus is on the merchant to verify the purchase, but given the nature of the biz in question, you'd think they'd be a bit more discreet, esp. for a small order. I'd think any order under $100 should just be processed...
"America's freedom lies in cannabis."
"Prohibition is the gateway to fascism." -