Worst company

Hi I am not pleased with Mtn, I took a 3 year phone contract with Mtn for a Huawei p30 from 2020 to 2023 which I paid each and every month without defaulting, upon reaching the end of the contract they called me to take something new and I indicated that I will not be taking anything as I am under financial pressure I asked for the balance and I was told the contract has ended. To my surprise money was being deducted way after the contract had ended, where is the airtime going to because I am not receiving any benefit to that hence I took back my money as the phone had been paid according to the agreement, now the account had been taken the legal department and these people pester me, I constantly ask what is the balance but they refuse to give me the balance just the other day a woman called me to ask when am I paying and I asked what is the balance, she asked for my date of birth which I told her then she told me I was lying, what kind of service are you giving people. Even if I wanted to take another contract with you people I would not give you the business. I just want the complete balance and leave me alone