I am sorry to hear that the rings are not as you hoped for, it's not what we like to hear....
I am not too sure what the Green / Black marks are, maybe you have an allergy to 9ct gold or it could be a reaction of some kind between the ring and perfumes or hand creams.
If you are worried about the rings or feel that they really aren't what you want then please do send them back for a refund, I would devastated to think you are wearing rings of ours you don't truly love!
Kind regards,
Gary Ingram
Managing Director
The Diamond Store.co.uk