The request sent out has gone completely unanswered — it's worrying.
Tips
usage
A variant of the more common 杳无音信 — 音讯 and 音信 are near-synonyms ('news / word'), though 音讯 slightly emphasizes 'information/report.' In practice the two forms are interchangeable.
mistakes
讯 vs 信: 讯 has the 讠 speech radical + 卂 (speed) → news/report. 信 has 亻 person + 言 → trust / letter. Both work here; 杳无音信 is older and more common, 杳无音讯 feels slightly more modern/journalistic.