A related question --

! just called Delta to book an award flight on CO (I verified that an award was available for my desired dates on CO.com), all flights have CO flight numbers, one segment is, however, operated by Cape Air (a CO partner). The starting and ending airport is only serviced by Cape Air, and the airport code is not even recognized on Delta's website (MAZ - Mayaguez, Puerto Rico). I was told that this would not be possible to book.

Is this true or should I do the "call back thing" until I get a more informed agent?