Yellow paper concert ticket for The O2 show

I lost my yellow paper ticket stub for the show at The O2 Arena yesterday around 6:30pm. It's printed on bright yellow stock with a red serial 'ST-4882' and a barcode along the bottom. The seat details read Section B, Row 12, Seat 24, and there's a small coffee ring stain on the top edge. I think I dropped it near the entrance by Gate B when I was leaving the concourse at Peninsula Square, London SE10. It has sentimental value—it's for my sister's birthday, and I really need it back or a way to replace it ASAP. If anyone found it, please drop it at the box office or message me; I can meet in central London today.