MFC Financial Control Mess causing client to lose money and be threatened by inaccurate arrears amounts

MFC has been sending me emails and SMS’s stating that my account is in arrears and that I must pay my account within 10 days. However, my account is paid through a debit order which they control and arrange. Upon contacting them, to enquire why my account is in arrears and why they have not debuted my account, they stated that I had made an arrangement for a payment. None of which was true, and I instructed them to just debit my account as they normally do. No one could explain to me why my account had not originally been debited and why they automatically just placed my account in arrears without running their own debit order. The call center agent then stated that the debit order would go off the next day and the account would be updated. The account was debited the next day, however MFC has now debited my account again with the same amount! Therefore they not only don’t control their own financial controls by ensuring their own debit runs are done, but have no controls to prevent an excess in payment! If they don’t do their own debit run, they threaten their clients with immediate credit and legal action, while the fault is actually on MFC’s side by them not doing their job in ensuring that their clients accounts are debited as per contractual agreements! This is ridiculous!