Did you have three on-site interviews or were these just on the phone? From your description it sounds like all were on the phone since the interviewers did not

Did you have three on-site interviews or were these just on the phone? From your description it sounds like all were on the phone since the interviewers did not know you had already been interviewed. Phone screen people are just checking if you are worth bringing for on-site. They cannot possibly make a "hire" decision as their output is either "no" or "maybe". So, most likely, you had been rejected either by one of the screeners or for some random reason. But it won't hurt asking somebody higher up if you really want to work there.