worse medical aid internationally

My wife cancelled our medical aid last month with Bonitas, which they said we still owe them money for stuff they didn't pay. We payed the outstanding amount by eft witch they confirmed recieving it on the 26th of August, to only debit the amount again on the 1st of September, When called them to correct this, they told i must go reverse it by my bank, which means I need to fix there problem.