Health Squared won't pay R450 ambulance fee for it's 90 year old dying member

My 90 year old mother, Shirley Doris Calder, was transported from her home to Hospice on the 18 March 2019 where she passed away the following day. I approached her long standing medical aid scheme, Health Squared, to pay the R450 fee to Ambumed Rescue for the ambulance to transport her to Hospice. After explaining that we needed an ambulance urgently as the patient was to weak to be taken by car and an Ambumed ambulance was readily available Health Squared agreed via email to settle the account and in fact said they had but now will not furnish me proof of payment. I continue to get letters of demand from Ambumed Rescue. My emails and telephone calls to Health Squared remain unanswered and unresolved. Shocking response to a loyal member. Joan Petterson - daughter of the deceased