Through VFS Global (also where you would pay for Priority visa service) you can, as of last week, purchase courier service. Options are one way or round trip. I only purchased the return label through them and included it in the my package that I sent from my local UPS store. Simple. The return label was $134, however, and my one way label to Sheffield through the UPS store was only $83.
This may help all of those who are having trouble making UPS acct.