My complaint:
You say 1 in 10 chests has a joker card , thats not so. On the 16th , I bought almost 300 chests , and I did not get any new cards, then on the 17th , I bought over 500 hundred chests and got 2 new cards.
Suggested solution:
What you should do, is put a new card in every, say 25 to 60 chesrs you buy, should have a joker or a new card in it.