How much does the card cost?     What is the validity of the card?     How much J$ can I redeem per visit?     What happens to my J$ when my card expires?     Can I use multiple Jumbo Rewards Cards to redeem/earn J$?   No, only 1 Jumbo Rewards Card can be used per redemption/earning. How do I check my J$ balance?     What if I lost my card? Will I lose my J$ also?     How do I sign up?