Duplicate debit- No assistance in resolving matter.

Faulty deductions from personal account, loans department cannot confirm what the problem is and when it can be resolved, went into branch, they where not of any assistance at all. Latest FNB statement received via MMS confirms account is up to date, (21/07/2018), with NO ARREARS. FNB States account is in arrears with R3541. ( fail to understand how the account can fall seven months behind only a space of 40 days from last statement) The normal amount has been deducted 24/8/2018, (agreed date was 25/08 contractually) and the two debits of R3541 two consecutive days in a row, and maybe again tonight, cannot tell as the bank is of no assistance. Recordings available, as well as last statement sent, contradicting FNB's comments, if this affects my credit record, i will report it to the banking ombudsmen for resolution if FNB fails to resolve this.