£5 Off Bedding - No Minimum Spend at M&S (Sparks card holders)
If you login to your M&S Sparks card you might find any offer for £5 off bedding. There seems to be no minimum spend you you can pickup 2 free pillows, £1 pillows etc.
Take a look in your account and see if you have anything

Join M&S Sparks loyalty scheme for free. You earn "Sparks" as you shop which turn into rewards. Plus, in the past, members have received emails giving £5 off shopping; early access to sales; and invitations to special events.