More complicated answer - there is a certain type of pack in which you can select four different clans - if you specify Jungo and three other clans, then chances are that you'll get a Jungo card. However, there is a caveat... if memory serves me, you only get three cards in the pack, so there is still a chance that you won't get any Jungos.
Currently, it's impossible to buy a pack that contains only Jungo characters. The pack that gives you the highest chance to get Jungo only characters would be Elite pack (highly improbable though), unless the staff release nothing but jungo for a few months in which case, the New Blood would give you only Jungo then.
You could to buy Ctz?But I never have cos chances are that you get more by buying cards. Then selling the ones you don,t want,and buying the ones you do.It,s more fun that way ,plus you get used to the market.