Instructions:Stumbled across this one after finding that my beloved 'LOVEFILM' discount had expired :(
The link I found this one on merely says that there is a £50 discount but does not give any further details. I redeemed it on a case worth £78 and got £25 discount.
I tried it out on a more expensive case but the voucher is only valid once, so unsure if a more expensive case will generate more discount.
Hope this aids a very merry, credit crunching, festive season.