2009 MTN account not cleared Paid up Letter was available since the

I had an account with MTN IN 2008 were they sold the account to MBD debt collectors. I settled the account in 2009 MBD issued the Paid up letter to me. 2023/02/01 when i open a new account , i was told my old account has not been cleared. I was told to request a Paid up letter from Mbd then email it to cim_legal@mtn,co.za. An automated response was sent with reference number and 3 - 5 working days for response. I sent an email in 22nd March 2023 its 7 days without any response. today i went to the stone towers mall for further assistance. i was told they can not assist me. I dont understand why can't i call legal directly so this issue can be cleared urgently..