My question involves a consumer law issue in the State of: Missouri

Sorry if this is in the wrong place...

A few months ago, my mail carrier knocked on my door and said that there was postage due on a box. My son answered the door and asked him how much it was for, and he said 75 cents. My son asked who it was from and the carrier acted like he didn't want to answer that. He then got very rude and told him that it was cold outside and that he should just argue it out at the post office, and handed him a slip and stomped off. I called the post office and complained, and the manager said that she was sorry, she knew, he was an idiot, didn't care about his job, was going to quit in three weeks, and there wasn't anything she could do.

In talking to the district office about the problems here, it came up that my son was a minor when this happened, and they thought that was a pretty big deal.

That mail carrier never quit and is still the regular carrier here.

I contacted the eBay seller who sent me that package, and he said that it was in a flat rate box and that there was no postage due when he received it back.

Now I wonder if the carrier faked the postage due so I would give him money.
A couple of months ago I heard a huge crash when my mail man came up, it sounded like he ripped my mailbox off my house, luckily he didn't, there was just a big envelope folded in half shoved in there.
It also happens often that packages say they've been delivered when I have not received them.

Then last Thursday I had received mail for someone I have been told for legal reasons to not accept mail for, so I wrote "not at this address" on it and put it back in my mail box. Friday he just circled the "or current resident" and left it in the box. So that night I submitted an online complaint in which I said that "whatever idiot" is to pick this thing up and take it back.

Saturday, he didn't come at all, and I noticed that my recent Amazon order said that the carrier said that the front door was not accessible. I watched him walk right by my house.
I don't have a gate, I don't have a dog, that Saturday all that was blocking the way was a 16 oz bottle that someone threw at the bottom of the sidewalk that meets my steps, my steps because I live on a hill, and perhaps the branch of an apple tree that hangs over the steps, which he frequently takes apples off of. I talked to Amazon and they said that the carrier was USPS. I called the main USPS number and complained about it, and they said the manager here would call. She called while I was out, so I wasn't able to reach her. She said she was in another office and to call that number instead. No one answered there, so I called my local office's number again, and someone answered who said he was "no one with authority who was just holding down the fort because no one else was there." He told me that my package was still there, he didn't know why it wasn't delivered, except he heard through the grapevine that there was an "incident" last week and that that's probably why it wasn't delivered. It sounded like he thought the carrier was just mad.

Monday the carrier didn't come to my house again. Again, I watched him walk right in front of it. I called the main number again and they said that the manager told them that she already talked to me and everything was fixed. I never talked to her.

Finally today she called, and she said that the carrier didn't want to come up here because of the "hostile environment." I asked how the environment could possibly be hostile, and she replied with "You called him an idiot, Ma'am."

I never directly called him anything, I never even spoke to him.

She repeated something along the lines of "I'll do my best to fix the problem, I need to know that he won't be threatened" multiple times. How is saying someone is acting like an idiot in an online complaint to their manager, a threat?

For a "threatening, hostile environment", he always parked right in front of my house for years because I gave them permission to put a pick-up box on the corner of my property. Only last Saturday did he start parking on the opposite end of the block.

The manager said that she would send the other mail carrier out to give us our mail today, and he did with no problems, and that she didn't know what to do after that.
She said that the carrier was entitled to his route. Aren't I entitled to my mail?

We live in a small town, so I wonder if this carrier is related to the manager somehow. She said during my conversation with her today, when I brought up how he was rude to my son last January, that she thought I must be mistaken with a different mail carrier because this one doesn't act like that.
I feel like they're conspiring together to make themselves seem like victims of a non-existent threat so they don't have to deliver my mail anymore simply because they're mad.
The mail carrier is mad because he got turned in for his unprofessional behavior,
and the manager is mad because I went to a higher office instead of her so she could no longer cover things up.

This has been a very stressful situation, I'm waiting on medication to come in that I must have in order to breathe.

Is there any recourse I can take?