Sure notice a lot of people have problems with the USPS, but for me it is just the opposite as they been wonderful for me and only had one problem was a detector i sent to Canada and it took 2 1/2 weeks to get there, but I think it was because of customs. One went to Korea and it took 3 days to get there, One to Poland and UPS wanted $165 with it taking about 4 weeks while the USPS price was $63 and had it there in 10 days. In most cases anything I send East or West takes 3 days, but South takes 4 days, UPS takes anywhere from 5 days or more and one even took 15 days to get from Georgia to me in ND.
Lately for the past 2 years the package have been decent, but before 90% at least were damage before I got them.
FedEx is another story as out town has about 10 house in it and they don't seem to be able to find my business as we are the only bar and cafe in town and we have had items sent back because they could not find the address, this last week we got 3 packages for people that live on the other end of the block and just left on our door step. Last fall we had 8 bigger packages for the house behind us dropped off in our back yard, so we are not all all happy with FedEx.
Bought 2 detectors off the auction site and were shipped USPS and didn't work when I got them, but customers said they worked great before they sent them and we had to turn in a claim on them, one was a bad coil when sent to Whites to be repaired, while the other one had the battery contact completely corroded away and was told it had been apart and someone had tried to fix it, but the USPS still paid me for the repair cost even though it wasn't the Post Office fault, but it take about 6 weeks to get my money back.
This is why I have more faith in the USPS than UPS or FedEx
I was told you have to wait around 10 or 15 days if the package don't get there, then they can put a tracer on it and find it for you from USPS, so I would ask your post office to put a tracer on it as your receipt should have a date on it when you sent it plus a tracking number you may not be able to track, but they can at the Post office and see where it was last.
I hope your detector shows up for you in the next few days,
Rick