[unruhjonny]

these days there are few skilled people in the auto parts industry - even in dealerships where they are selling only parts for new cars they mostly employ the caliber of people who need to start with your vin to find anything for you;
That being said, you need to take a similar approach to RA as you do at just about any brick and mortar auto parts business;
You need to look at cross reference ect to find the problems in their listings.

I do this every time before I click "order";
Parts for our Caliber SRT4 and Cobalt SS are often listed wrong (parts for the lesser models which do not interchange are listed as being for our cars) - the cross reference will tell you if it's wrong...
As to the wrong parts being sent;
I did have a single instance years ago, before they went wholly automated so I was able to speak to someone and get it remedied - these days, you need to be extra careful, because you CANNOT speak to someone...

It is pretty hard to argue with a fourty to seventy percent price difference for the exact same parts... which is what I have observed - especially on my Cobalt's brake components.