Yes, if Oswald didn't receive his rifle then naturally he would complain and Kleins would be expected to have to some sort record of how they handled his non delivery but alas no evidence appears to exist. Meaning that Oswald's rifle was delivered.
But then you’re assuming that Oswald ever ordered a rifle.
I supposed you consider your imagination about what records would be kept to be evidence too. Everything that pops into your head is “evidence”.
Let see… if the postal service had shipped and delivered such a package they would be expected to have some sort of records of shipment and delivery. Meaning that it was never shipped and delivered.
Hoist by the petard of your own bad argument.