a girl always calls me that i am best friend in her eyes but i said to her that i have been bored of her by talking then she said to me that she will never call me and disconnected call.
No, you're not wrong. If someone of the opposite sex is THAT attached to you and you can't stop yourself from yawning, it is good to cut the connection quickly.
I didn't understood your using of word "Bored". Was she entertaining/interesting before? There can be many decent ways to express that you are not interested in her, considering not to hurt other person.
It's your personal choice to have any future relations with her or not. Just doing it gracefully makes you a sensitive human, and much respectable in society.
@JaggedLittlePill she has boy friend. so she must call him. i just told her truth which is in my mind. i really felt bored when she talked about her boy friend