Settlement

So I call Nedbank yesterday to settle an account that is 8 years old and already been written off, they quoted me an amount in Dec 2014, they then quoted me another amount yesterday which is another R3000 on top of that, I asked if they can substantiate the difference and she sends me details until 2011, which doesn't mention why the sudden rise, so Mpho says sir, I am sorry, the quote generated in Dec 2014 was a mistake.I get a call an hour later from her supervisor saying that he can give me 25% discount, which amounts to the quote given to me in Dec 2014, its strange how Mpho can say no straight up and yet her supervisor can accommodate me.I sent her the POP yesterday and said I need a paid up letter, she says no, she can only send me that after 3 days when it reflects on their side, fair enough, so I said how about giving me the necessary by Friday, once again without any reason, she can only supply me with the letter on Mon or Tues....why...I still don't know....my frustration is that there is no customer satisfaction, she doesn't seem to care.I gave Nedbank their money so why must I still beg, its terrible to be served this way