Y can this happen

Ring ! Ring ! Ring !
I pick up the phone ...
and the chat history is abt this:
He: Kumar pls.
Me: Kumar is not available now,can u leave ur msg?
He: Kumar not available ah ...
Me: Ya, Can u leave ur ..ah msg, Or can u call back later af...
He: Can u call him to call me back?
Me: OK
He: Tan, from CTS .
Me: CTS? Tan? (then i write down)
He: CTS!.
Me: CTS TAN. OK.

"Close" the phone and Kumar is come.
Me: Ya, Kumar. Tan from CTS call u.
kumar: CTS?
Me: Ya. he say is Tan from CTS.
kumar: CTS? Tan? I dont know ow.
Me read and read the note i write just now: Yala, CTS tan.
Me: I dont know ow, he say Tan from CTS. his sound very soft 1.
kumar look at me : mmh ....
Me: ah ....
finally find out.
Kumar show me a name card: is FPS it's?
then call to FPS.
ya...
is GOON from FPS. Not TAN from CTS.

the conclusion is. the phone is damage.