Here's the thing: Even with the best effort and intentions things will go wrong, it's inevitable.
However it's how the store/supplier handles the issue that differentiates them.
P&P? A simple example: A few years back I bought one of those little plate hangers made of two pieces of wire and springs. However the packaging was of such a nature that the heat used to seal the item onto the cardboard virtually melted the covering coating on the wires to the plastic over the cardboard. The plate hanger could not be removed without damaging it. The actual item was cheap.
I sent an email to P&P. Shortly thereafter I got a call back, offering a replacement. They had investigated and agreed the packaging was definitely not suitable, having tried removing the plate hanger unsuccessfully in one of the stock items.
I did not want a replacement offered (would mean taking down the repainted plate hanger etc - call me lazy

). However the point is that P&P followed up, acknowledged the issue and sorted the packing issue out while offering to make good with me. That is customer service.
Then again I have had issues where the store simply could not care ... and I never go there again.