MySQL - How to select records that all child has status in ('A','B')? -

for question, have 2 tables.

tb1 names cases
tb2 names calls

have select case calls contain status in ('a','b')

example:

case has 3 calls.
call a.1 has status a
call a.2 has status a
call a.3 has status b

case b has 3 calls.
call b.1 has status a
call b.2 has status b
call b.3 has status c

so, query should return case because in case calls status in ('a','b')

my query return case record contain call status not , b c. it's not correct

select  c.id cases c join calls ca on (ca.parent_id = c.id , ca.parent_type = 'cases')  c.status <> 'closed'  , ca.status in ('a','b')    group c.id 

could me, please?
thanks,
may

select cs.* cases cs join calls cl on cl.caseid = cs.title , cl.status in ('a', 'b');