She expressed her disgust at the programme by writing a letter of complaint.

她写了封投诉信，表示对这个节目的反感。

《牛津词典》

He fired off a letter of complaint.

他奋笔写了一封投诉信。

《牛津词典》

EXAMPLE: I wrote a letter of complaint to the huge company's president, but my letter was probably lost in the shuffle, and I never heard a reply from her.

我给这家大公司的总裁写了一封投诉信，但我的信大概就像石沉大海，从未接到过她的回复。

youdao

The live music company has filed a letter of complaint to The Royal Parks raising "serious concerns" about the tender and bid process for the new four-year contract up to 2017.

BBC: Live Nation may end 10-year link with Hyde Park