Like so many things in life, it depends.
For the most part I've had good experiences ordering from Wal-Mart. 3 issues so far:
1) last year I ordered 4 cabin air filters for the Sonata. 2 arrived. Called customer service and had a nice chat with a young man from South Africa who credited my account for the two missing filters and told me a little about his life. He definitely made the experience better.
2) Ordered some personal care items. One bottle of Cremo Shower Gel arrived with about 1/4 of the contents gone, and packed in a plastic bag so it didn't leak on the rest of the items. This was pure carelessness on the part of the packer as I doubt that the bottle sprung a leak on the trip to me and some sort of AI/self-correcting process intercepted the problem, bagged the bottle in-flight, and prevented the rest of the items from being damaged. This was resolved with an online chat and a new bottle was shipped.
3) Also last year, I ordered some Bluetooth ear buds and gym shorts. It appears that the earbuds were shipped from a local store, no problem, but the shorts came from somewhere else. I tracked them all the way to the last warehouse, on the truck for delivery, and then it went back to the warehouse and I got an e-mail from Wal-Mart saying that there was a problem with the address, that I should correct the address before my next order, and a refund will be issued. Keep in mind that this is the same address that the earbuds were shipped to as they were all on the same order. I'm still trying to wrap my head around that one. My suspicion is that the driver didn't have any other deliveries in the area and didn't want to trek the 40 miles from the warehouse for one delivery and then go back another 40 miles.
As always, YMMV.