You can find contact information for immigration courts here. If you are not sure which immigration court has your case, you can find this information on your Notice to Appear (Form I-862).
It can sometimes be difficult to reach a court clerk by phone. You should continue trying and make sure you are calling during business hours. Many immigration court staff members speak only English. If you do not speak English, you may need help from a friend or family member to translate during the call. You may also hire an interpreter.
If you have moved and need to update your address with the immigration court, you can file Form EOIR-33/IC. More information about changing your address is available here.
Disclaimer: The information provided here is for general informational purposes only and does not constitute legal advice. Immigration rules may change. For guidance on your specific situation, always consult official sources or a qualified immigration attorney.