Breach

I app**** for a discovery card a month ago and I received the card. The card was activated and anything was fine until yesterday when I try to use the card at a shop it declined. I call discovery card and they told me my card was blocked because of outstanding documents but no one from discovery contacted me for any documents. These was very embarrassing to have your card declined. This is a breach and very poor service from discovery card. Why accepting my application and blocked my card?