Legal handing over

I have been having a contract with MTN since 2024 and half the time I always delayed with making a payment, last year December my bill was R2500 and I made a payment of R1000 so today they say that I'm owing R3800 and I called to ask why that ridiculous amount and the response was that they handed me over to the legal department. I asked them don't they call a client first before they do that or maybe an email to alert you that if you don't make a payment or arrears, we gonna hand you over. As much as they can see by how a person makes a payment, no matter how little one is putting an effort, they still want to see a person deep in debts, it's not right, they need to review their system.