I lost my job at my work place what was I supposed to do?

I was a assistant manager but another staff member was unhappy and was sabotaging my job. (He was doing the job until I joined the company) he would do things to make me look incompetent move stock. I had put away in front of witnesses or report me for things I never done. He would also change my paperwork behind my back. I told my manager who refused to listen to me.

Now I've gone they gave this guy my job.

He even deleted company files and blamed it on me which I never did. I actually seen him do this also.