keep taking money from now and dont wanna cancel my account since I've sold my vehicle

I cancelled ,my account in 2021 and they still deducting money from my account with debicheck. 2 months ago I called them and asked how much am I owing and the said R1900 today I call to check how much am I left with they say I now owe them R2800 because my account has not been cancelled. so double deduction is made in my account and my bill keeps on increasing. this company is a ****. They keep taking and taking and no one is taking responsibility..