ParcelForce Consignment if you return 4 or more parcels
If you have 4 or more parcels to return I recommend ParcelForce Consignment which gives fully trackable 48 hour guaranteed delivery and tends to be around £12* for any number of packages going to the same address (max 15). I tend to go through phases of ordering a lot (and regretting it) so this works for me. In the past, I've returned 13 parcels for £12 in the past (a personal best or worst depending how you see it!). Coupled with cancelling the orders under DSR I "lost" less than a quid per parcel.
*The consignment price is calculated by adding together all the parcel weights so my combination of garment, cheap jewellery and beauty stuff has never pushed the cost over £12. The service is better, in terms of the level of trackability, than 1st class signed for and you can set the level of insurance (I opt for £100) but if you were returning say 5 items of fine jewellery you could set a higher level of cover and it would be cheaper than RM Special Delivery for each parcel separately (£6.22 each whether it's a small parcel or a large letter).
Few Post Office staff offer this as an alternative unless you ask for it my name: "ParcelForce Consignment" If you have more than 8 parcels they can accommodate them under the same consignment number even though their menu only has space for 8 items on their first dialogue page on the post office terminal. So don't let them fob you off; they can take 15 parcels per consignment! I'd be lost if my little local PO ever closed down, they're more clued up than the main office in town!
I always opt for £100 cover for the consignment (I know it's probably less than the total returns' worth.) If you're returning a couple of Lulu Guinness bags, a South Sea Pearl item and a Perricone TSV you can pay for higher cover. But the fact that your sack of goodies is fully trackable from Post Office to QVC depot, means I'm prepared to risk it. If you can show via tracking that QVC have had the consignment received at their end you'd have proof that your 6 parcels had arrived back and QVC should refund on that basis so you wouldn't have to claim against Parcel Force. Each parcel within the consignment has it's own unique ParcelForce barcode label attached by the PO.