Can filing bankruptcy stop a wage garnishment?

I got a call from cash call who has threatened Wage garnishment and when I told them I was filing they said that unless I it is completed before I'm served, the bk will not stop the garnishment. Is this true? She suggested I make a $200 payment to avoid being served and that would buy me 30 days. Are they just trying to take my money? I dont really have the money to pay them AND pay the filing fee of $300!