Could you add option to buy Premium using Premium SMS technology? If you don’t know how, I believe dotPay offers such feature and I believe others as well.
The reason I’m asking is because I have little to no money on my real account… but have (due to my agreement with operator in which every month I have to up my account with 50 pln) 150 pln (about 37 EUR) which I have no use for. And it’s common thing in Poland and I believe other Slavic countries as well to have more money on your pre-paid phone than you really need due to various agreements like one I’ve mentioned. Dunno if it’s such issue in countries to the west from Poland.
In conclusion, I’d love to buy premium, have money, but have no way to.