ER Consulting accounting department - Poor interdepartmental communication

Family member had an emergency consultation at Nelspruit Medi Clinic operated by ER Consulting. Claim was confirmed and paid by medical aid and ER Consulting keep on sending e-mails and cellphone messages that payment is outstanding. Two calls were made to ER Consulting account Dept to provide payment reference and one e-mail sent to confirm payment and this morning another set of messages and e-mail was sent indicating account is outstanding. It seems as if ER Consultation accounts dept and creditors do not speak to each other