An employer is not allowed to withhold pay unless the employee authorizes them to do so--that's why they can deduct for health insurance or 401k, for example, because you authorized it. (The one exception is that they can withhold taxes without your consent.) If you did not agree to let them withhold the money, they must pay you...of course, unless you have an employment contract protecting your employment (such as by limiting grounds for termination), they are free to terminate you for not proving proper information, if they want to, unfortunately.