Guilty as charged! I never check my interest charge.They must be inside the law to charge you this ammount as the CC industry are on the ball!
On my account recently i'm on a minus amount of up to £150 because of a refund but as they are a "credit" account I will see no interest.
A convenient way to pay safely but comes at a cost I believe. Pay them back £11 just to see the minus sign ...lol. By the way I use Barclaycard...only the best...sigh.