English correction: A friend of mine asked me to call her one day but I could...

[Jessy1]

A friend of mine asked me to call her one day but i could not call because i got sick....Later we met in yahoo and we chated.
She asked me why didn't u call me?I wanted to tell her that I could not call because i was sick.How would I have told her correctly......"I couldn't call u because i got sick on that day" or i didn't call u because i was sick... or i am sick.It looks stupid but help

[Mister Micawber]

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Please review your work first and capitalize every instance of the pronoun I.
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Native English teacher at Mister Micawber's

[Jessy1]

Thankyou Mr Micawber