It is not smart to avoid responsibility. Keep your word. Acting like you didn’t know is the same as not being truthful. Read: Proverbs 24:12 (click on link below and read today’s Scripture).
http://bibleresources.bible.com/passagesearchresults2.php?tp=31&book_id=24&c=24&passage1=Proverbs+24%3A12&version1=51