Betis had pursued a deal for the Brazil international for much of the summer, but the market shut on Friday with no deal concluded.
Haro reflected: "We had an agreement with Barça for Rafinha and the player was pushing to come to our home.
"The problem was that he did not want to accept a long-term contract with us. So, we had an agreement with Barça, but not with the player!
"All this happened in the last 48 hours of the summer transfer window."