BlackBerry Curve 9300 on 02 fully working, hairline scratch on screen ?

Only used for 2 months, unfortunately the only imperfection is a hairline scratch on the screen (Shown in picture) . No idea how it happened! Otherwise in perfect condition, fully working. feel free to ask any questions :) Must pick up either today (05/092012) or Tomorrow (06/09/2012) before 1pm