Urghh! What a mess they put you through!
What is interesting to me reading these customer service experiences, is that it doesn't seem to correspond to the price of the goods sold. I shop at very inexpensive places for the most part - Old Navy, TJ Maxx/Marshalls/Ross, H & M, and Macys, and I've had no trouble with returns from online to the store, or at the store as long as I still have tags.
I've even had sales assistants take a store credit off one item I returned and apply it to another I'm keeping and bought previously, or match online prices -- they for the most part are just neutral or happy to help, and so of course, I'm always happy to visit that shop again.