Poor client service delivery!

I have paid up my accounts in full with Nedbank on the 5th of February in order to close my account with this bank. I requested paid up letters on Wednesday, 12 February and was told that my accounts reflects as cleared and that the letters will be sent to me. On Friday, 14 February I still haven't received anything. I can't understand why it takes so long just to send paid up letters after confirming that they can see it is cleared and why it takes 8 working days in the first place of not hearing anything back from this bank other than me phoning after them. When I requested settlement amounts on the 5th of February, I received it within minutes! Why am I now to wait almost two weeks just for paid up letters????