Hi all , advise would be really appreciated , had a message from a client yesterday whose roots I did 3 weeks ago and is due for a re-do next week , she text with photos to say that I had missed some of her roots , she attached pics and it was half way up the back section of her hair , just a bit put out and makes me feel bad but I personally would have mentioned it when I saw her next , what would you advise I do ? Have said I would reduce her next bill , hate it when things go wrong !!