I have an update, since I started this thread.
I think QVC Customer Service has really improved over the last few months. My returns are credited in about a week now. And, on my most recent return, I contacted CS with my tracking info and the credit was put into the system right away. Can't ask for more than that. Other retailers are taking at least 2 weeks, except Amazon, which is immediate.
I realize I may just be having a lucky streak and others are still having problems. That new rapid credit process described above really does work nicely tho.