Well, I've finally got a MTV card through a U.K. sat store online. It is a little more expensive, but at least I have it, there's no hassle in activation or charging & I can alway recharge whenever I feel like through the online store.
The card now comes as a detachable SIM card type(great if you have a CAM with a SIM slot). So now I use it in my T-Rex CAM with my Sly card