Not updating their system as per my Payment

1. I received an e-mail from Tasneem on the 24th August 2017 asking for payment. I rep**** on the 24th that payment will be done on the 25th August 2017. Payment was done on the 25th August and proof of payment was emailed to her with a request for a settlement letter. I sent her later the day again an email requesting for a settlement letter. On the 29th August I sent her another email requesting her to update the system and provide me with a settlement letter and have not received any response from her. 2. I reported the situation to the head of department Faizal on the 30th August in which he promised to update the system and provide feedback it is now the 31st August and again I have not gotten any response. 3. I received an email from Tasneem on the 31st August 2017 at 13:21pm that urgent payment is required after I have sent her the proof of payment and she does not respond to my emails. 4. This is very frustration as it is reflecting badly on my credit report. 5. Ackermans is harassing me by the total amount of telephone calls received daily even after working hours.