I am an administrator of a small facebook group and one of the members got out of hand.?

[Mr. Curious Rides Again]

He posted a very offensive and inappropriate picture of a extremely misspelled note from a co worker, and he as well as two others made comments that where just down right vicious and not keeping in the theme of the group.
Being a disabled person, and having a zero tolerance to this type of bullyism, I reacted diplomatically and utilized what I had available to me and clicked on "remove from group" icon under their names, and removed them.
Well I have been approached in private messages, stating remorse and apologizing for the transgression occurrences, so by agreement with the other members, they will be allowed back.
One problem, the FB group page won't allow them to rejoin or even submit a request to join. Oh, it won't allow me to add them either.
How or what I have do so they can rejoin, or are they banished for good?

Thank you for any response

[Carling]

A leopard can't change it's spots. And neither can empty heads change their thoughts, it will backfire on you sooner or later, stick to your zero tolerance rule