MTN IS A ****

I made an online application for a cellphone contract in 2024 for a package that comes with a Samsung A55 phone. It was delivered to me with no document that explains the billing nor did I get any as I was signing an online contract. The agreed amount of R350 was debited from my account. Two months later, I noticed that the MTN App says that I now owe Five thousands and couple of Rands. I phoned to the service provider to request for a statement and I was told the only statement is that which is on the App. Surprisingly, the App only reflected the amount owed with no statement. I called several times to want to understand why the amount was so high but I couldn't be assisted. I then decided to discontinue to use their simcard. On the 6th month I noticed that I am now owing Nine thousands and couple of Rands and two thousands was debited from my account. The following month, R3400 was debited. Last month, R4300 was debited and this month I decided to shift my salary to another account before being debited but I noticed a declined deduction of another R4300. I don't understand how long am I gonna be paying for whatever I'm paying. I don't have any document that shows the amount I owe, the reason for the debt and the outstanding balance. I don't know where my money is going, I am so much disappointed with MTN. May the company please stop debiting my account unnecessary so because I don't remember signing a contract that stipulates that they will debit my account with such large amount, the telephonic agreement was R350 only. I'm sinking deep in debts because of the unplanned fees debited from my account. Please help