My employer has seized my resident card for to pay...

Recruitment costs and fines which come within recruitment procedures are made by the employer under Article VI of Ministerial Resolution 52/89, which states the following: “The employer or his representative legally signs the recruitment application form prepared by the Ministry for such purpose, and the form should include obligations as follows: : The employer's commitment to sponsor him / her and hold responsibility for the recruited worker and his / her costs in accordance with the contract concluded mutually with no violation to the provisions of the labor law
Consequently, you have  file a complaint against the employer at the Labor Office as you have previously indicated, and the passport after handing it over to the employer, as it must be returned.