Unless otherwise stated it'll be the same as other cards, which in the UK is at least: 14 days cooling off period starting the day after you receive your card (to notify them, then you have another 14 days to actually return it). If faulty you can claim a full refund up to 30 days, 30 days to 6 months and the retailer gets one opportunity to repair or replace before you can claim a refund, 6 months to expected product life (but claim within 6 years) and burden of proof is on you to prove product is faulty and then you can claim a partial refund.
On top of that, Scan currently guarantee satisfactory quality for 3 months of normal use and will refund, credit or replace.