NS&I slow to pay premium bond money

Has anyone else noticed the NS&I are being rather tardy on paying premium bond money. I asked for some to be taken out after the draw, and a week later they still don't show it had been sent.

Also, I actually won some money in the draw. It shows I have won but has not credited my account.

Are they delaying deliberately to gain a couple of extra days interest? Rachel - I think this is one for you.