credit Harassment from MTN SOUTH AFRICA

Good afternoon. I would like to express my dissatisfaction with MTN South Africa. I have a cellphone contract with them from 2012 to 2020, if I am not mistaken. I authorized them to debit my account on the 15th of each month. They kept on delaying payment until I was in an area. They then handed me to debt collectors, Munnick Basson Dagama Inc, for payment arrangements. I comp**** with them and settled the amount of money owed. The account was settled on February 26, 2022. Since I requested my settlement, it has not been given to me till this date. The only letter I have is from Munnick Basson Dagama Inc. that proves that payment was made. MTN South Africa has now transferred me to another debt collector, saying I owe them money for what I do not know. They have now handed me the Nimble Credit fund and have been calling me to pay for something that I do not know. I will not tolerate such harassment from MTN as they do not communicate with me regarding their payment. I would appreciate MTN providing me with my settlement and must reimburse me for turning in my name at the credit bureau.