was told full-time hours

On Wednesday I received a message from the director I work for stating a promotion in pay and hours. On Thursday she asked cor a meeting to tell me I would not be getting full-time hours. Then on Friday I received an email saying that my hours were cut to about 9 hours a week due to a client leaving and it would take about 8 week to on board a new client for me. Is this legal? I am in North Carolina