FNB you are the worst!!

Good Day, On the same topic!! on the 24th I called the credit card department and spoke to Naledi, We made a long term arrangement for me to pay R1100 from the 1st Aug and received and sms right ofter regarding the arrangement and again on Wednesday 25th July i received another sms confirming the arrangement..... this morning I check my account an this morning the amount of R3805.42 was debited off my account?????? I just called the credit card dept. again and after holing for 12min Elizabeth took my call..... after being on the phone with her for 36min nothing was solved. According to Elizabeth, why they took the R3805.42 was for previous months that was not paid???? My understanding of an agreement is that from the 24th July payments of R1100 will go forward starting from the 1st Aug..... please let me know if i am incorrect? They should then told me that R1100 + the outstanding amount of R3805.42 will be taking!! This in the 3rd time this happening...... and all my other accounts are being affected because of this, i am trying to make arrangements in order to pay all my accounts but Due to FNB not honoring arrangements I am failing to honor my arrangements with my other accounts. I am really tried of this now, can someone please assist me please!!