For the vast majority of people, once they enter the US they want to remain, for at least as long as their authorization permits. Those who find that they do not enjoy life in the US are usually allowed to leave freely as long as they have obeyed the law. However, in some cases, after entrance into the US, someone wishes to leave but requires public assistance to do so. If this is the case for you and if your distress is caused by your entrance into the US, you can petition for assistance in leaving the country by filing USCIS Form I-243 (Application for Removal).
Number of pages of the form: 2; this form is filed at the USCIS office closest to your home in the US.