Poor Client Service

I called Fnb to settle my account for the credit card budget facility. The lady assisting me gave me an amount to settle and advised me to transfer money to my straight credit card. I did so then i called again requested settlement and it was still that same amount. The consultant asked me if she should settle for me on her side i said yes She did and confirmed that i owe R0 on budget facility. Then 2 days latter an installment for budget went off from my straight facility. I called and male consultant told me its interest from the budget facility I ask why was the.interest not included in the settlement value. He couldnt answer he promised to call me but didnt A week later i called. A female consultant told me its not interest but an actual budget installment. How so because i settled the acc. She had no answer. Its now 3 weeks later no solution to my query Why an intallment or interest when i settled the acc. Why was this not included in the settlement value. I need my credit card account to fixed asap.