The second you file your Petition and Schedules with the court, a federal statute declares that all debt collection activity is stayed (i.e., stopped). This is why the court immediately mails a notice to all of your creditors that you filed bankruptcy. This automatic stay is one of the most beneficial things about filing bankruptcy.
One your debts are discharged, usually a little more than four months after you have filed your case, the automatic stay become permanent for all debts discharged.
The notice from the court that you have filed or that your debts have been discharged is usually enough to stop the harassment. by creditors.
Sometimes an incorrect address is used for a creditor and they do not get the notice, or if the creditor is a large corporation the wrong department of the corporation gets the notice. In that case, they might keep trying to collect the debt.
Usually all it takes is a letter (not a phone call) referencing the case number and the court where you filed to get them to stop. They might have to pay civil penalties and attorney fees if the don’t stop in addition to any damages you have experienced. Most creditors are aware of their exposure to civil penalties and attorney fees and are highly motivated to avoid them.
If they do not stop, then a lawsuit is in order to get a judge to order them to stop,and order them to pay the damages, penalties, and attorney fees.