Dept chair crumpled my resignation lettr

I am a year into this training program in a public hospital and then at one point in time I've decided that this institution is not for me. Workload was overwhelming, boss has an anger management issues, I cannot tolerate my senior's attitude anymore hence I wrote a letter of resignation.

Talked to dept chair and TO about this and got an "okay sige" reply. The next day I submitted my paper, hoping to have a graceful exit from the department however found my paper in the trash bin, crumpled, with no whatsoever explaination.

I asked the higher-up hospital administration about it and suggested to write directly to the chief of hospital to inform my last day effectivity, I did and they've accepted my letter, without the signature of the department chair.

It's my last month with the department and I think this last month will be a hell of me, now having anxieties on finishing my last render of service in the hospital. Are there any ways to waive the 30 days render of service? I just want to get out of this institution so bad and not see the face of the dept chair anymore.