MTN's Predatory Pricing Model

Having bought several large pay-as-you-go data bundle over the last few months, my latest pay-as-you-go bundle for 20G expired somewhere between 26 and 27 June 2020 by my reckoning, and then I started being charged out-of-bundle rates on these dates. This is despite having specifically selected options not to have this done. I reckon I have been unexpectedly charged well over a R100 for this. I think this kind of pricing model is predatory. I would like a refund for the out-of-bundle charges please.