Complain against the insurance claw.

Complain against the insurance claw which they never said me before & i have submitted the related documents to the insurance company at 03/08/26 & and today they mailed me that the condition where my wife get admitted is not covered.my wife admitted due dehydration ,loose motion ,nausea .so my doctor suggested to take admission 24 to 48 hrs of under observation.at that time I asked my relationship manager for this situation at that time he told me yes it will be covered under insurance but now when I submitted all related document they denied my claim & said this all symptoms are under pregnancy.but when the hospital doctor fill the claim form B they tick mark the illness column not the maternity column.