Txt: CRISTAL to 51500. Only one entry per mobile per day. Purchase required. Winners will be asked to mail in their original till receipt for proof of purchase in event of winning claim. This challenge will be announced notably on packs of 10 BIC® Cristal® Original Black, Blue or Assorted ball point pens, or packs of 10 BIC® Cristal® Fun ball point pens (“Promotional Pack”), www.biccristalchallenge.com and press releases.