Currys PC World

I found a a good deal on a laptop on Currys website and called them up to order. Everything went fine but on the day of delivery I got a mail saying my order has been cancelled. I called up customer care only to find out that they don't know why it was cancelled and I can order again at same price, which I did. But guess what, I get a mail next day saying order has been cancelled. Again !!!!. This time customer care said that its because my order did not pass security check and they don't know what it means. I don't know what sort of security check is this. I use the same debit card for online shopping all the time and never had any issues. This was a Christmas present for someone and it was totally ruined for no reason. Thank you Currys. Luckily John Lewis offered me a price match. I am never logging on to Currys again.