Cant use coupons

[crustyfolker]

So i was looking at the Dovpo Riva why no Black Birdy or full Gunmetal, ok i won 20% off with the spinner. Yet this cant be used towards the Riva. It makes no sense as i could spend the same amount on say 3 items and i get the discount. whats the difference between 20 % of the Riva ( making it £72).
and 3 oxva rta's and get the discount so £99 goes down to £79.20 from £99. Looks like buying ia Riva from China now.