Waiting for status approval - how to contact ?

A family member sent in their status application in July 2025. We received a letter with a file number and also received their primary documents back. But since then, nothing. Tried calling and received a message that phone service isn't currently available. Sent an email to the address on the letter and haven't received a reply either. Does anyone have additional information on how we can get an update? It has been nearly 6 months now.