I am a reluctant shopper of NM and continue to be because I generally buy what they sell and sometimes it has the best deal (not often). They also have great Christmas decor. My friend works locally at a NM so I also try to support. All that said, their customer service for online retail is SO BAD. It's been bad for years and doesn't improve.
I don't have a single episode to recount but there have been multiple "problems" with my orders at both NM, Horchow, and Bergdorf Goodman. Also, when I try to call and get help about a product, it sounds as if the person is reading off a cue card and cannot answer or agree with me on basic things. For example, a shoe size 41 - is NM equating that to a 10 or 11, and they act like I'm speaking another language. This is NOT high end shopping whatsoever.
I've had shipping delays, failed attempts to price match, randomly cancelled items. These are not $50 orders... these are sometimes $1000 orders and deserve much better service and communication. At one point I had FIVE MONTHS of trying to get a refund for an item I returned that NM said they never got (even though they refunded the other item in the box). I had to do a credit card dispute to which NM fought that too! All over $150. I said "either send me the item back or give me the refund." After 5 months and about 30 calls, I got my refund. You're fighting me over $150 for an item I did return when I spend tens of thousands there a year?
It seems as though NM has tried to change their game a bit recently but it continues to fall short. Wait times on the phone or chat are extremely long; the link to "customer service" on their site is down and I have to find their number elsewhere, etc.
There are great examples of online retail out there. Revolve Clothing and ShopBop come to mind.