Packs purchased at online.gaijin.ru do not appear in Steam client. Loggin in using non-Steam client solves the issue.
PS. this issue is already reported here: http://forum.star-conflict.ru/index.php?/topic/35806-%D0%BD%D0%B0%D0%B1%D0%BE%D1%80-%D0%BD%D0%B0%D1%91%D0%BC%D0%BD%D0%B8%D0%BA%D0%B0-%D0%BA%D0%BE%D1%81%D0%BC%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%B8%D0%B9-%D0%B2%D0%BE%D0%BB%D0%BA/
is reposting stuff from non-bug report forums here useful?