You can't write a resignation report. Once you submit this report, it means that you have offered to terminate the labor relationship. There is no economic compensation.
I suggest you consult a local lawyer, because your problem is complicated and needs to be determined by combining your existing evidence, such as whether there is labor dispatch and whether the post office's reasons for dismissing you are legal and compliant. At the same time, it is suggested that you properly keep relevant evidence of labor relations, such as labor contract, uniform, payroll, work permit, etc.