I asume you are in the USA, the best corse of action would be to contact the American Roller Association and give them the ring number. The registered keeper has a reponsibility to claim the bird from you.
It may not be able to fly for many reasons, injury, exhaustion etc but they will be able to advise you.
If the number you rang has told you he sold the birds he should be able to tell you who he sold them to but i suspect he may just be fobbing you off.