Exactly what I was going to reply, word for wording! Bizarre! Basically £5 worth of cereals free if you spend £25 on F&F clothes. Sort-of.
What a strange promotional offer (lol)
Thanks OP, I did this earlier accidentally! Two versions of Special K Protein (Berry and Nut) are on CheckoutSmart for £2 cashback each, and they're priced at £2.99. So two boxes of cereal and the £5 voucher for £1.98 after cashback.