Closed account handed over to attorneys to collect bank fees????

I started a small business and decided to open a bank account with FNB. To make thing easy I also open my personal account with them. We also asked our staff to open account with FNB.

We soon realised that FNB is not the right bank for a small start up business. Service is bad and unnecessary banking fees

We then asked FNB to close the account and opened a account with Standard Bank.

How an attorney calls me to tell me that I have to pay R300.00 on an account I instructed FNB to close. How can they hand my account over to an attorney for banking fees. The account was inactive for months.