FNB credit card closure

I have been trying to close my credit card account for several months now with no success. A few months ago I requested that this be done in a branch and they only assisted by decreasing my credit card limit to R0 which doesn't make sense to me. Ever since then FNB has been charging me for a credit facility fee and putting my credit card with a R0 balance into a minus and it is really annoying. On the 29th of January, I was given forms to fill on and sent to the email address provided. The following day I noticed that yet more fees were deducted. I accepted this level of poor service for a while now but I have run out of patience. Because of this, I will not continue any services with FNB.