Usually this happens when you try to pay using wrong payment system.

If you are from Russia choose RUB currency and pay using Russian payment system (Robokassa).

If you are not from Russia choose USD currency and pay using PayPal.
PayPal supports debit and credit cards payment, without registering.
Just choose second button on checkout.

If your payment keep failing message us support@www.site.boosterx.org
and we will find different ways to make you a PRO user!