hi guys need some help.I started in a salon a few months ago and on my first day i was given a client with greenish brown stains on her nails. she said her doctor had said it was water mould. my salon had been putting overlays on this client and had got her to sign a disclaimer. under duress i have worked on her nails with the highest standard of hygiene. anyway the stains had almost grown out, but she came in today with a new green/yellowish stain on her nail and i refused to do her nails. i dont understand why this is happening. she blamed a previous salon for the last lot of stains but i know i have done nothing wrong. why does she have more staining. what is it? HELP