Ok, this might not work, but at worst you'll have £30 in gift cards...
1) Nectar are doing 2000 nectar points (£10 in store, more on offers) when you spend £30 at Viking. You have to load this on through the Nectar website.
2) Quidco give 8% back on Viking purchases (exc. Apple or TVs) with no restrictions
3) Viking sell One4All gift cards which can be spent in lots of places, Amaxon, Argos, etc.
So, if this all works you could by £30 gift cards, get 8% (£2.40) back through Quidco and £10 worth of nectar points.
I've had Quidco pay out of gift cards from Viking before, so I know that works, but if the nectar points also work then it would be a great deal. At worst you'll have the vouchers, so maybe worth doing if you are planning a purchase anyway.