Discount code invalid - not applicable (possible Missell)

andrewash316_2

At this stage I won't name, names. 
A popular sports retailer has an offer on at the moment to obtain a 10% discount off your first app order..
I've gone and tried to order and the discount code keeps flagging as invalid. 
I've emailed the company to ask if their is an issue and they have come back to me saying exclusions apply.
The website doesn't quote any exclusions or terms and conditions on its advertising. But in the app it does say excluding sale items. 
I've read through the websites terms and conditions (found after trawling through its site) and it has a dedicated area for promotions.. but the link comes up as 404 website not found. 
Even the app doesn't have any links to any formal terms and conditions or promotion terms.
I've taken screenshots and sent them to the company to question it's validity, but from a consumer, where do I stand on this? 

Thunderbird-4

Not sure what you mean by where do you stand. 

Often codes don’t include certain things, without naming the store and saying what you’re trying to buy it’s hard to give an opinion.