An ABC investigation has discovered gift cards that have been tampered with are being sold by Australia's biggest supermarkets, with charges even being laid over the issue.It is leaving shoppers confused and stressed, and raising questions about whether this is linked to a multi-billion-dollar criminal scam. The packaging felt "kind of funny" in Lavkesh Arora's fingers.The Melbourne tech worker had gone into Coles that day eager to buy Apple gift cards, lured by a supermarket promotion that gives people extra FlyBuys points when they purchase them. Lavkesh Arora bought several Apple gift cards with signs of tampering.(ABC News)"I wanted to buy…