15-01 UPDATE: Xsolla seems to have fixed the issues with SMS-payments.
After weeks of delay (which wasn't our fault) we have finally integrated the new payments system. The main difference is the addition of ProtoCoins, our own virtual currency. 1 USD = 100 ProtoCoins. You can purchase any amount of ProtoCoins using Xsolla's PayStation. After that, head to the Premium features page to spend them. You can also still pay directly with PayPal, just as before, without bothering with all this coin-business.
Nothing has been changed in the subscriptions and packs themselves, except the 7-day subscription is no longer available.