We contacted the supplier repeatedly about the delayed shipment, but to no avail.

我們多次聯絡供應商詢問延遲的貨物，但毫無結果。

The manager tried to reschedule the client meeting, but her efforts were of little avail.

經理試圖重新安排客戶會議，但她的努力幾乎沒什麼用。

Our customer service team apologized several times, yet it was of no avail to the angry caller.

我們的客服團隊道歉了好幾次，但對那位生氣的來電者毫無作用。