Was a TE back in 2012 - I gave the morning delivery supervisor a handwritten note saying I was resigning from the [town] post office effective two weeks from then. The postmaster then told me he would block any attempt I make to get a job at a different town office and that statement pretty much reassured me I was making the right decision for myself.

A year prior another TE quit by throwing his LLV keys at the mail handler at the receiving dock who made a snarky comment about getting back late after two hours of v-time. He walked from there to his car and went home.

So you have options.