Mtn account

I had a cellphone contract with MTN, and the account was handed over to MBD. I have been making payments to MBD for almost 2 years. However when I called MBD to request a statement and settlement letter I was informed the account is no longer with them and it was "bought" on the 18th November 2022, yet I have consistently make payments. I was told to contact MTN as they can no longer have the file. I tried to contact the MTN customer care, who transferred me to credit control then to Legal but still no assistance. Just as I was about to pay off the account, it is moved to God knows where, without my knowledge or any communication from MTN. What happened to the payments I made to MBD after 18th November?