well you are not foolish I would have expected the pattern to be included, hence the term "KIT".
I believe I would maybe write a little note to the shop owner and explain my shopping trip to their store. How you discussed with the person waiting on you that is was your first such experience and how disappointed you were when you got home and found there was no pattern included. You were under the impression that was why the term KIT was used. ...
and might you suggest that in the future when this type of discussion occurs with a customer that they might mention the pattern is not included. Had they done that you would have made an additional purchase with them. Howere since it was a drive for you, you ordered the book on line. I would try to keep the note pleasant but let them know that for a newbie you need help.