Harassment

I am very disappointed in the way I have been getting harassment calls from Mbd call center agents about a debt that settled with them last year 28 may 2024 of a amount of R408.92 from Hamechoice,and what is worse they were provided with proof of the payment via email and this is resulting in a negative impact on my credit score,I don't know what it is more that must happen on my side to have this company loo through their system to see that I have dealt with the debt and now it keeps on having interest on it.i have paid the account in full can I also request I get a paid up letter.let us stop with this mickey mouse thing it's frustrating