Standard bank paid up letter

Hi, I'm struggling to get a paid up letter from standard bank for my overdraft account. Standard bank handed me over to MacRobert Attorneys in September 2018 since I was owing them R16300. I have been paying directly to my standard bank account and the last payment of R4260 was made on the 25th of June 2019 and I received a notification that the amount was received. It has been a mission for them to issue me with a paid up letter, I have tried them several times and they always tell me that I will get a letter in 2days. I also tried standard bank and I was told that, although it's showing that the account has been paid in full but MacRobert Attorneys will have to issue the paid up letter since they have handled the case. I feel like it's a bit unfair because when a payment was missed, they will call me now and then to ensure that I pay. Now that I have settled the account they are playing mind games with me. I hope that this issue will be sorted soon because I need to use the paid up letter.