Discovery Cancelled Policy NO reason

My daughter has been for a couple of Psychology appointments. but was Never diagnosed with a mental illness of sorts. Discovery just canceled her membership and refuse to pay for her treatments at the Psychiatrist. she has only now been diagnosed that she must see a Psychiatrist. Not on any medical aid was this a factual confirmation. Her dad and i went thru a divorce and she needed to speak to someone as this was traumatic time. Only now been told while on discovery she suffers from anxiety. Discovery called us canceled the policy and refuse to pay. This is not even diagnosis as yet so can’t be factual on any application as it is being diagnosed only now. Absolutely pathetic