Door slammed to the face

Several weeks ago I interviewed for a job for a good company to advance my knowledge elsewhere. I knew it wouldn’t go over with my boss as I was told he doesn’t take kindly to workers who plan on leaving the company. I made my manager aware that I would be departing of my current position and she ended up telling the owner who in turn fired me for no reason and making things difficult. Because of that I am with barely half my pay and rent is due soon. Having half the rent might cause a problem. Being betrayed by a comer employer is by far the worst thing to ever happen. To think you could leave a job safely and transition into a new job. To be stabbed in the back. I trusted they would do good by me as I have by them. Have you ever had an employer do you wrong and fire you before you finished up your two week notice? Tell me your stories.