As pre-loading the card would not be something I would need to do more than once, and for a specific reason, do you think I might be able to arrange to do it over the phone? Anyone have experience with such a thing?

Trouble is, call centres, different folk who have a set script they must keep to, no room for common sense etc etc ...... The last time I tried to get them to lift my credit limit I felt like chucking the phone at the wall - it's all coming back to me now . It made no sense at all - we are about as financially sound as you can get - and felt like they were depriving themselves of business, which is what happened of course.