$250! That's a hell of a price unless it was a very professional. As someone else said I think you should claim your money back if this message came AFTER you'd paid. Luckily I've now got the hang of singing from memory, but in most open mic style clubs a single song sheet is normally ok, but I think a book or 'smart' device are not really acceptable. Put the effort in the try memorize a song or two it's easier in the long run