American Express
Creative currency rates

On 5/10, I went to American Express to exchange the following currencies:

320 Euros: the official exchange rate was $1.54373/Euro on 5/10 But AE paid me at a rate of $1.472298316/Euro: This means that I received $471.14 instead of $495.75[minus a $3 processing fee]

680 Guatemalan Quetzal: The official exchange rate was $0.13415/ Q but AE again had its own "creative" exchange rate of $0.106396200/Q. It should have been $91.68 but I received $72.35 [minus another $3 transction fee].

Can someone please explain how they come up with their own lower rates when one sells foreign currencies?
In December the GQ rate was ALSO at $0.13 and they had applied that rate WHEN I PURCHASED SOME QUETZALES.
On 5/10, the teller claimed that these were the official rates but they were grossly lowered for AE's benefit.

Is this even legal?

Company: American Express
Country: USA
State: New York
City: New York
Address: 822 Lexington Avenue
Phone: 2127586510

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