FedEx Smartpost - worst service in shipping I have ever had

I apologize in advance for the long text - but wanted to warn people about using this service. Anyone who has used it can likely relate

I ordered a hat online and the only shipping option was FedEx Smartpost - so I chose that. That was Thursday of last week. I don't recall if the shipping option said FedEx SmartPost or just FedEx. Now I have never had any issues with FedEx or UPS or any of those guys, but I have had many, many issues with the USPS. My tracking number has been showing all along that this package would likely be delivered Tuesday August 16th (on the FedEx tracking website). As recent as yesterday morning it said it was out for delivery on Tuesday. Usually if this is the case I can expect the package on my doorstep when I get home, or it is delivered by 8pm the same night. I came home and didn't see a package. I went online and checked my tracking and it said "Delivery Exception - Unable to deliver - please contact local post office to pick up or reschedule delivery." I saw that it said post office, but I called FedEx first, since they were the shipping company that gave me the tracking number. The lady on the phone said that the Post Office was delivering it and that I would need to contact them. This was obviously confusing - given that I never got a USPS tracking number. I called the Post Office number and of course it is automated and reaching a representative is near impossible, so I left my number and they are supposed to call me back.

I called FedEx back and went through the same routine, but this time I asked what the USPS has to do with a package that was being delivered by FedEx. I doublechecked by shipping e-mail to verify that there was no USPS tracking number. The lady on the phone said "oh you need to add the numbers 92 to the beginning of the FedEx tracking number for the Post Office to help you." This was the first I had heard this and it is not on their website. I tried not to be short with her but I asked her how I was supposed to know to add the random numbers 9 and 2 to the beginning of my tracking number and she really didn't have an answer. The post office website is saying to look at the notice left by the delivery person on my door. No such notice exists - not on my door, not in my mail box, not on the ground by my door not in the bushes or anything, the notice does not exist.

I have since researched this a bit and it turns out that FedEx Smartpost is some horseshite business relationship between FedEx and the USPS that helps shippers in saving money, not entirely sure by what means at this point. Either way, I can't get in touch with the post office yet and the automated voice said it would be about 15 minutes. This was an hour ago.

Any of y'all been burned by FedEx Smartpost? Tips?

TL;DR - Do not use FedEx Smartpost to ship or order items - it is worth the extra couple of bucks to use a service with a good reputation. I can't locate a package i ordered.