You said you anticipated problems when you posted last week in response to the Winnipeg situation. And without prying into your personal affairs as to how you managed to accumulate so many MCOs, it is next to impossible to ascertain why AC has taken the position it has. (Should we consider it racist, I don't know. That is your basis for this agent's attitude towards you. It sounds extremely bizarre behavior to me.]

All I know is that whenever I buy airline tickets, I use my credit card. So whenever I have changes, my card is credited with the original charge (less any cancellation fees if applicable) and the receipt credit note is clipped to the back original of the initial ticket purchased. I then get my replacement ticket using the same, or another, credit card.

Cash transactions, and those originally handled by travel agents, are the ones where I can see MCOs being used. As well as problems arising on several fronts: MCOs have become a major means of circumventing currency laws and are now commonly used for money laundering purposes. Anything issued in Mexico is sure to raise a flag. [As for the exchange rate, that's a whole other matter which does not sound defensible if you were not offered the prevailing current rate.]

As I say, without prying into your personal practices, it is impossible for us to comment on the response you received from AC. My main question would be how you came by more than $3,000 in MCOs issued in Mexico? But that is none of my business, though I suppose it could be AC's. Particularly if they were multiply issued, cumulatively assembled MCOs, and had no original ticket vouchers affixed to them as you readily admit.