Paid up letter after settlement of the account

I settled my MTN account in February 2022 however this company SSDA is not giving me a paid up letter, i have been calling since February but they are not helping me with a paid up letter. ********. Now the same MTN account is on my credit report under the company with no name, how can i owe two companies with one account. Shapiro Shaik give me my paid up letter please