As per the TOS:
Please keep in mind that The Knot Message Boards are not to be used for posting complaints and defamatory comments about vendors. All defamatory posts are subject to removal at The Knot's sole discretion. We are concerned that you be treated fairly and that other brides are warned of any bad apples in this business.You have the option of contacting the vendor directly, or if an official complaint is appropriate, you may contact the Better Business Bureau at www.bbb.org.
Your posts will be removed, but I do recommend that you go post over on the Knot's sister site The Wedding Channel.