SERVICE NOT UP TO STANDARD

I hope someone can assist.I phone Direct plenty of times to find out why my account was not debited as arrange.They debited the FNB bank and then asked me do do a payment.I made the payment and now they say I am in arrears by R400.Direct should carry the arrears cost as it was not my fault that they did not deduct as arranged.Call centre people full of attitude.Asked for a statement and did not received anything just a sms to remind me of the arrears.