If I was to say the words in this scenario, my voice would change
while I would be saying the word "complaining". It would change, in
order to express that from my point of view, I don't see it as
"complaining" but as a statement of the facts.

Verbally, I would do it exactly the same way you've described. Whether Klingons would do any differently, I don't know. Tonally, Klingon seems identical to English.

Any answer about the written form will be about our Latin-character transcription system, because we don't know this sort of thing about pIqaD. I would typically put the word between asterisks or, if I have formatting available, I would make it italic. You know, the usual techniques in typography.

-- 
SuStel
http://trimboli.name