саппорт ответил следующее:
Greetings !! Apologies for the inconvenience caused !! We have been facing some technical glitches with our Bank's Payment Gateway and some international cards are not being read. We would request you to kindly make a fresh application once again after a span of 9 hours atleast and then pay. In case you have already tried more than thrice then you have to re do the entire application form once again as after trying thrice the application gets locked permanently. Make sure you delete the browser history and cookies while doing so.