Very bad service, no customer care whatsoever

I've been trying to cancel my LTE subscription since May 2022, I've stopped using the router in June already, sent numerous emails but I've only had someone call me twice over non payment. And after explaining my position to her, she said she would alert the cancelation team but yet another month has passed and I keep receiving invoices. Does it not reflect on their system that this person doesn't use the service, I should've contacted MTN then and gotten LTE package straight from them not these problematic brokers. I have since installed fibre through a different company and I really don't want anything to do with supersonic ever.