Claims rejection

Our son broke his arm two Sunday's ago and was rushed to a hospital to be treated at Netcare Med24, to our surprise the claim was rejected because it is out of plan claim however hospitalisation is fully covered by the plan, when we asked the consultants to provide us with hospitals they cover fully they Could not claiming we should upgrade our plan, however my other son was once treated and claim paid at mediclinic hospital when attended to in an emergency, what is more surprising is both hospitals are on their list of hospital we can use yet we are told our claim has been rejected with no valid reason, if we had just went to any other Dr out of the plan and gotten this response we would have understood but this was an emergency at the hospital making having this medical aid useless to have