just so I know exactly

[frindle]

Hi! Could you tell me what the underlined part means in this context below?
I understand that the woman thinks the speaker is wasting her time.
Am I right or is there any other meaning in it?
Please help me! Thank you.


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"It's Daniel. I was on the quiz show (on the radio)"
"I'm afraid you're too late, it's already started."
"No! I know! I was on it. I got cut off!"
"I'm sorry, sir, you're too late!"
I realize it's a different voice to the one who normally answers.
"Please! They need me for the knock-out! I got cut-ff!"
The woman lets out a long sigh, just so I know exactly how much of her time I'm wasting. "Hold on line."

 

[5jj]

I understand that the woman thinks the speaker is wasting her time.
Yes, and she lets out a long sigh to suggest Daniel is wasting a lot of her time.

5