To be fair it seems about right for companies these days. Maybe make a little on interest etc? The only bit I see on the website regarding speed of payments is this.
Fast Payments
We will start to process your payment within 24 hours of receiving and testing your device. You can choose from Bank Transfer, cheque or Argos vouchers.
Right ok. I've only sold to Mazuma before, who do have the 2 hour payment process. Doesn't really matter I suppose.