I can see both sides of this.
I remember biting my tongue on here a few years back, when someone said that they were returning a craft kit, but keeping some of it 'to cover the outward postage'. Someone else posted on the same thread that they had seen a kit they liked, but only wanted part of it, so were considering ordering and taking out what they wanted, returning the rest. I also know someone personally who was decanting some decleor into a one of those cheap travel bottles when I arrived. She said she was returning a kit but keeping the aromessence as she used that and it would 'only get thrown away.' All of this must impact QVC's profits whatever their MBG is.
I have drastically reduced what I buy from QVC now, but even so I have things listed on my account as returns that shouldn't be in my opinion- a Vax cleaner that was faulty-AND the replacement they said they had sent out after I asked for a refund, which I never received as it was sent back before the courier attempted to deliver it. I ordered a ring for a birthday present for my daughter, which sold out whilst on air. Instead of a £30 ring, I had delivered some earrings with diamonds and pearls listed as over £180. Luckily for them I am honest and returned them-but on my account, it just says I returned the ring. A nail polish set I ordered for my daughter never arrived-listed as a return. The wrong size birkis sent out, my actual size had by then sold out- again another return.
I won't be at all surprised to get one of these letters. I won't worry though as anything I desperately want (which is rare) I can get elsewhere. The peddling of the MBG is annoying- they should be more honest.