Sometimes i dont feel like a friend

This is how i feel at times .
Sometimes i felt as if i dont feel like a ''friend'' to others because some of them take me for granted . what makes me says so ? Well , as u can tell whether people are treating you like friends or ''friends for granted ''
1 : They ask you for help when they cannot find anyone else except you .
2 : When they have no friends around them fer a moment that will come to you .
Tsk ~ . it totally piss me off like seriously  !