Just from the reported comments on here, I get the impression that the Facebook posts seem to come from those who are naive, lazy, stupid or slavishly devoted to QVC.
I never return those stupid letters from QVC when you report potentially lost or undelivered goods. Q are already getting plenty of my money in the P&P, and even though it's the cost of a postage stamp to return the letter, I really resent it. Why they can't send it out by email (let's face it, they have the blummin email) and allow it to be returned by email for free, I don't know... it's not as if us purchasing a postage stamp would benefit them at all!
As far as I am aware, I've never had any issue with Q questioning the veracity of my complaints about non-delivery... probably because they get enough complaints about the various delivery services they contract for to know it's entirely possible.
I've always found the CS staff absolutely fine. I think it helps that I am always polite and calm with them... although I'm sometimes very persistent. I can imagine if you have uncle tom cobley and all ranting at you, eventually your professionalism may head for the hills after a long day. You catch more flies with honey than with vinegar, as the saying goes!
I think it can often come down to the fact that Brits are, in general, very bad at complaining. We often wait until we are completely infuriated before we will actually complain, and then we let rip. I think we need to have some masterclass complaining training to get further with CS departments everywhere.
There are so many lovely and unique alternatives to most Q jewellery, and often at much better prices... I only buy it as gifts, so am an occasional buyer, but I've had great service using Etsy (with goods coming from a considerable difference overseas arriving much faster than Q's standard efforts), and really lovely quirky gifts suitable for the wearer's interests. Who cares if Lola Rose is a well-known "prestige" brand? Most recipients aren't going to be wowed by that, really. Better to show the recipient that you are interested in their lives and get them pieces to reflect that.