It may be a pain because of the extra step, but you may have to resort to buying a UGC code and then adding the Crysta by applying that code. It would essentially be just like buying a UGC card from a store, you just would be purchasing the code and getting it from an email or directly in the online store's shopping cart instead of having a physical card with a code printed on the back.

You can find them on Amazon and Newegg sometimes, but they are available at various sites online. Here's their page to online retailers:
http://ultimategamecard.playspan.com/buyonline.html

They also have a find a store page there that may help you find someone locally to get physical cards. For Brazil, they have links to E-PrePag and Paymentez for finding local stores.
http://www.ultimategamecard.com/wheretobuy.html