Me & You Mobile Charged me R1165.05 even after i cancelled my contract.

I cancelled my contracted and migrated to prepaid then they still charged my account R1165.05 even though my contract was cancelled. I went on to their website and spent a whole day with a lady called Ashmika who did absolutely nothing to help me. I reported the problem at 11:30 and all the way through the day while waiting until after 5pm nothing had been done. They just keep apologizing and saying they've escalated the problem to management. They blame technical errors which they cant explain. I've had problems with them since before 2019, its just gotten worse. They have one customer service agent and they're apathetic to the needs of their customers. I had a terrible experience.