The next time I do something like a ball joint or tie rod or whatever, I’m going to put the old busted one back in the new box and try to return it. Curious to see what happens.
Ok - not something I’d do, but this thread is making me wonder…
Most shops order the same parts from the same parts shelf from the local parts store that you do, Napa, ADV, O’Reilly’s, AZ etc etc for most of the parts, they might have some bulk items such as hose clamps, bulbs etc that the DIYer sees, but the ball joints are pulled from the same shelf for Pros and DIYer…
Now some of the big chains that can afford to and have the space for, have some parts inventory but still order mostly from reg parts stores… At one shop I worked at, we had a lot of Moog items as well as alt/starters, belts, tensioners, brake pads/shoes and such, I still spent 20K + on outside vendors (Napa etc etc) I would guess probably 80-90% was outside purchases, not in stock parts…
And yes I have ordered an alternator before and opened the box to find a very used water pump inside, just as only one of many wrong parts showing up… 
I had them ship the incorrect parts also . Order some Monroe OE Spectrum shocks. They shipped the cheaper lower end line instead so I sent it back and once again they shipped the incorrect shocks even though I told them the exact name and model of Monroe shock I needed so I had to ship those back also and they finally got it right on the 3rd try .
Cheaper than replacing a EV battery pack .
Have you ever considered ordering auto parts on Amazon?
They’re a LOT easier to deal with, when it comes to returns
That problem could probably be solved if Rock Auto’s staff had better training, and better qualifications just to be hired. The downside is they’d have to charge more for their products to pay for the training and better qualified employees. Is that a compromise you’d be ok with? Are you willing to pay more for better service?