Purchased the USB Modem with a view to using it to keep in touch with my business while abroad for a couple of weeks. I was lead to believe that the £15.00 top up would give you 30 days in the UK and somewhat less abroad, given that we are still saddled with massive unjustified "roaming" charges, so I was expecting 10 to 15 days. Little did I know that in fact all you get is 24 hours!! Any credit is completely wiped 24 hours after your first use!! Not only that, you have absolutely no credit left to top-up on line, so you are forced to call "customer service" and listen to 15 minutes of drivel before you can talk to a human. So on top of Vodafone scamming you for £15.00 you get saddled with a massive phone bill - in my case it was Euro 23 from Germany!
Customer Services could not give any explanation why my credit had evaporated, and when it happened again the next day I had to resort to buying a local dongle. At least the German version clearly states in the manual that use abroad is limited to 24 hours. They also have a much better way of charging: you get 5 minutes free, 15 minutes for 0.39, 24 hours for 3.49 etc. so you can see exactly what you are paying for.
All of which takes the "mobile" out of this so-called mobile broadband device, if you want to go abroad. Guess I will need a second suitcase for all my locally sourced devices - has to be cheaper than being mugged by Vodafone UK!!