Manager changed the release date suddenly

Team , I was given the release date of 31st Dec 2024 , suddenly today I got an email from the secretary of manager that you are getting released with effective 30th Sep 2024. Without any discussion they changed the date , without discussion they changed my role in ultimatix as well. What step should I take ? The email which the secretary has sent is a rough email with no respect in it , I gave my 9 years in the project. What should I do now ?