You have 15 days from the date of the bank levy to file paperwork to object to the levy. Once filed your bank will hold the funds until you go to court to have your objection heard. The filing of a bankruptcy will stop the levy from occurring and the funds will be returned to you.
If you fail to take action timely the funds will be transferred to your creditor and you will not be able to get them back even if you have a valid defense to the levy.