INCONSISTENT DEBIT DATE

TELKOM HAS BEEN DEBITING MY MONTHLY PREMIUM INCONSISTENTLY AND NOT THE DATE WE HAD AGREED ON !! FOR 3 MONTHS NOW MY ACCOUNT ACCOUNT IS IN ARREARS BECAUSE YOU AS A SERVICE PROVIDER HAVE FAILED TO DEDUCT ON THE 30TH OF EACH MONTH AS PER MY CONTRACT . WHAT IS HAPPENING ??? CAN YOU PLEASE ADVISE BECAUSE I HAVE BEEN TO SEVERAL BRANCHES AND NONE OF YOUR EMPLOYEES ARE COMPETENT ENOUGH TO EXPLAIN WHY THIS IS HAPPENING . I DONT HAVE MONEY TO PAY FOR ARREARS ESPECIALLY CAUSE IT IS NOT MY FAULT THAT YOU CHOSE TO DEBIT BEEFORE THE 3OTH OR RANDOMLY DURING THE MONTH WHEN THERE ARE NO FUNDS!!