Nokia 6233 — keypads colours gone

I am having one mobile pcs. Of your company nokia 6233 handset I had purchased this mobile on dated 7/5/2008 from aditi communication the prombles with this set is that the colours of keypads colours has gone . The colours of these keypads is white .It is now difficult to exactly recognize the number and letter printed on it . The owner of the firm (from whom it had purchased this set ) say that there is no gurranty of colours if this keypads .Kindly let me know if this is the case. Kindly relpy me if the firm must change this mobile set or not.