I thought maybe I can act as a bit of a meditator...or here's my attempt at it, anyway!
I realize great deal or not so great deal, one expects to get 100% satisfaction and if any less, we aren't too happy. We do pay, so, there are expectations. I say, don't look a gift horse in the mouth! That is, however, when it is a gift and not something you payed for. But, ah, people have different definitions of worth and whatnot. Dealing on the internet is a tricky thing and sometimes things go sour due to mis-communication, which CAN occur and this appears to be such as both of you seem like good guys.
Maybe your calls didn't carry the best timing and 202020 should've sent the stuff via UPS rather then USPS if he said he'd do so. If you really did get a good deal though, maybe you should let it slip; forgive and forget, you know? New grade 8 hardware is a good idea for mounting the hitch anyway. and the center caps, well...ya know, hitch and rims and whatever gas money you gave 2020202, it more then surely saved you a TON on shipping; shipping rims is expensive and a hitch is a b***** to ship! I know from experience. Try to look at it that way, maybe?
USPS has also lost a total of three packages in about 4 years for me. I don't send too many and I wasn't the happiest when it happened. Granted, all were very replaceable things (hence my using USPS) ; CDs, a bundle of photos from Costco, and an A/C adapter. I had confirmation slips and that was all which was left as proof those things ever existed.
Hope you guys can work it out in private and the thread can go away. I believe that, if this were eBay, this thread is like the equivalent of a negative feedback, and I think at worst it should be a neutral grey bubble.