Amazon.ca support is fascinating.
I originally got a Street Fighter V M. Bison preorder costume code that was already used when I tried to redeem it. Sending an email to support, I got a response apologizing and providing me with a code that included details of the SF V beta after it. I responded saying that I was looking for the M. Bison preorder code and the email suggested it was for the beta. They responded saying the costume was for Amazon.com preorders only and to contact Capcom, then get back to them if they say otherwise.
Given that the first three screenshots of the product page show M. Bison in the preorder costume, the Customer Questions and Answers suggested Amazon.ca purchases are eligible for the code and the Capcom Unity blog explicitly said "North America" when outlining the bonuses, I decided to contact them via Chat as the phone line was closed. 10 transfers to the "Games/Software" and "Support" departments later, the agent posted the code the first CSR initially gave and asked if that worked. I said that code came with beta details, but decided to try it anyway. ...It turned out to be the costume code. During that time, a transfer occurred but I immediately told the last agent that all is well. I needn't be transferred anymore and ended the chat.
I wonder if they just transfer customers to other agents if it seems like it'll be too much effort.