Bankruptcy Law Questions? Ask a Bankruptcy Lawyer.
Hi - my name is XXXXX XXXXX I'm a Bankruptcy litigation attorney here to assist you.
You're correct that once you file, creditors are IMMEDIATELY prohibited from continuing any collection attempts as under the provisions of the automatic stay: http://www.law.cornell.edu/uscode/text/11/362. Here's a link that explains what the automatic stay does: http://en.wikipedia.org/wiki/Automatic_stay.
You should inform your employer of the bankruptcy filing and provide a case number XXXXX other information to prove that bankruptcy has been filed in order to stop the garnishment.
Also, I would recommend that you inform your attorney that this creditor has said it will disregard the automatic stay and try to collect. Your attorney can file a motion with the court to stop it if necessary. Also, the creditor could be stripped of its claim against you/your estate for violating the automatic stay, so it needs to be careful as well.