Good! I hope they get rid of my carrier. There's not a day goes by that I don't get someone elses mail in my box. That scares me because she's probably putting my mail in someone elses box too. I filed a complaint with the local post office last month, and since that time, I've got three "warnings" from her. I hope she gets laid off, or fired.
You are completely correct to be upset about the misdelieveries. That your complaints are not being taken seriously reflects very poorly on the Postmaster as well as the carrier. No competetant Postmaster tells the carrier who complained, they just repriamand the carrier and put a note in their file. That you heard from the carrier is absurd.
What to do?
Call the Postmaster again. Tell this person you want the phone number for the POO (Manager of Post Office Operations for your area). If the Postmaster does not give you the number, call a large Post Office nearby and tell them you are trying to get the number for the Manager of Post Office Operations. You will get the number.
The POO, (like Winnie the POO), can transfer or demote a Postmaster on his own authority without permission beforehand from anybody. POO’s do want mail delievered correctly. There are regulations about acceptal error rates of delievery. The POO will help you get satisfaction. Your Postmaster will never ignore you again.