You don't have any rights unless you had a written employment contract for a definite term (e.g. a one-year contract) which is still in force or effect and which guaranteed your position and/or pay. If you did have such a contract and this violated it, you could sue your employer for "breach of contract" to enforce it (e.g. for monetary compensation for the breach). However, in the absence of a written employment contract, you were an "employee at will" and your employer could legally demote you and/or reduce your pay at any time, for any reason, withouit any prior notice. An employee at will has no rights in or to his or her job, or his or her title/position, or his or her pay--it's all up to the employer's sole discretion.