IMAS refusing to send me a Paid Up Letter

I had a vehicle loan with IEMAS Financial service, we however got to an agreement through their debt collector (ODBB Solutions) that I would settle the loan at R40 000, I settled the loan on or around 13 April 2022, Their debt collector advised me that they cannot give me with a paid up letter at the time and that they will only send it to me after 7 May. Came after 7 May, they are not sending me the letter despite several follow ups. I am not understanding what is difficult with writing a letter.