Glad they arrived @hshah - it sounds like you got two substitutions there. These will be because of the various production issues that were encountered during the project and at this point were pretty much unavoidable. You'll be able to request ring vouchers at a later date after things settle down and everyone has rings, and stock levels are back up again.
If it's possible would you be able to get the ring sizes check or use a micrometer to get the ID and check the sizes? Don't try to use a ruler, it won't work properly.
This way you can confirm what sizes you have, whether they're right for your fingers and whether you've received the wrong ones - then you'll be able to sort out whether to exchange them and what for.
I will take them to the jewellers and get them measured.
It would have been nice to get something with the packaging to tell me that they had put in substitutes :(