Don't count them out yet, though it seems you should have gotten them already. Panman may have gotten held up on mailing them due to the 4th of July and family gatherings. I would think if he got them out the following Monday that you should definitely be seeing them by today or Monday.
I will say that the USPS is definitely struggling. I live in a rural area and was expecting a package that tracking said was "Out for delivery". I happened to see the letter carrier's vehicle drive by my house without slowing down. About five minutes later I received a tracking notice via text that the package was undeliverable because nobody was at home to sign for it. I called the local post office and talked with the postmaster. I had my package handed to me less than 30 minutes later. The letter carrier either mistakenly passed by my house or intentionally blew by "to save time" and figured on delivering it with the next day's mail. The bald-faced lied given for the reason for not delivering the first time really hacked me off...everybody makes mistakes...but don't lie about it. That's not been the only issue with them. Today's USPS is definitely not yesterday's USPS by a long shot. Most of the time it works pretty good, though. Best wishes on receiving your seeds...hopefully today!