Charging/reloading my Ｖプリカ

So I just bought a Ｖプリカ at Lawson's because I want to buy stuff online and not have to use my US credit card. Everything went smoothly, except for the fact that the highest amount I could purchase for it was ¥7,000. At least one item I want to buy online is over ¥10,000, and if I order multiple things at once I'm going to go even higher. I'd like to put ¥20,000 on it. Is that even possible?

Solved: I simply bought another ¥7,000 voucher at Lawson. There's an option when you enter your code (on your computer) to add it to a pre-existing card. This may not be the most elegant solution, but it worked for me. Theoretically you could buy 15 ¥7,000 or however much you need. There is an option to buy up to ¥20,000 online but it appeared to require a credit card, which I obviously don't have. I also don't have a printer to print out a slip at home and take it to Lawson, but if you do that might work for you.