Most likely a problem at the post office. AI directing packages to the wrong place. Things have deteriorated since more companies started using AI. I've had some packages take interesting detours, get lost and then get found and sent on their way.
I can't imagine Cathe sending you the wrong package, then realizing the mistake and asking for it back. It could happen, possibly??? Maybe it's their first such error because of the volume of orders. Given what USPS is charging for shipping, I think they would send another package with missing items before requesting a return.
I'm glad you got it. I almost got the STS bar but it is 5 inches longer than the one I use.