Found 18th Aug 2015
Get a free PAYG SIM card from Vodafone and pick a Big Value Bundle from £20 upwards to claim an extra 50GB of data to use on 4G. The £10 Big Value Bundle only works on 3G therefore your extra 50GB will also only be on 3G so that's no good. (That is according to T&C's.) Works for existing Pay as you go customers as well. Promo offer only. A brilliant way to test out the Vodafone network out (although a little pricey to get the ball rolling) before committing to any contracts. I'm going to pick up one of these myself. Promo offer 11th August - 30th September. Enjoy.