False advertising or overcharging?

Is this false advertising or overcharging?

I had been with rain from late 2019, had my share of issues but more or less was happy. The way they advertised themselves were a no contract month to month ISP and having missed a few payments before came to understand that you don't pay you don't get the service which was great came to early 2022 I found myself no longer in need of their services I didn't pay but now I find them saying I owe them R1 426.70 when the plan I had with the was only R479.00 a month. How when we have or had no contract and the amount is supposed to be R479 only? This is really fishy, not sure if I should get the ombudsman involved again.