it may be that that position is no longer available. if that is so they have offered you an alternative position they are not sacking you, you must accept that, or leave of your own free will with no comeback for the company. as they have offered you another job. it happened to me, when i returned from holiday, everyone new before me.bite the bullet and take the job. unless your job is given to someone else, then you have a right to a reason for the demotion.