The first thing to check is that it's still a live offer. We tend to limit how long the deals run for - so we advise getting in as soon as you see it.
If the offer is on a specific discount code, double check the spelling and try again.
If it should be working but isn't, please accept our apologies that it's not and get in touch!
You can either use the live chat, create a new support ticket or call us on 01423 525750