In the US-- if I understand what happened to you-- there is nothing lower than a "booked no-show," ESPECIALLY if advertising has already been done. Unless there is a really grand reason for the no-show-- death, ER, ice storm preventing travel-- a no-show is expected to furnish a replacement for you to approve, and if they don't, word does go around-- tactfully-- what they did. One way it goes around is that bookers call an artist's past bookers to check reliability before offering a gig.

~S~