Waited a month have to wait two more just for paid up letter from FNB

I had a loan with FNB so Unilaw contacted me and they offered me a settlement with discount so we made an arrangement where I have to pay the amount off in 6 month time. The lady who arranged everything here naam is Sandy she works at Unilaw. My last payment went off on the 15th of December 2018 where she told me that as soon as the payment went through I will be provided with a paid up letter the december went by January is also over. Today I received a letter from Sandy that have been sent from FNB to here saying that I have to wait 45 working days to get a paid up letter which is ridiculous why should we wait that long just for a paid up letter?????? I have been waiting since the 15th of December 2018 a month has past now they want me to wait another two months the account is still open I don't know why they haven't closed it yet. Other institutions provides you with a paid up letter as soon as you finished paying them why can't FNB??????