******** Month to month contract upgrade

I am reaching out with regards to my contract linked to ***, Internet data Mychoice 50gb package. In September 2023 I received an email quoted on this email stating that my sim only package of R330 is discontinued and I will automatically be upgraded to a package of R450, and I quote " no action will be needed from me). To my surprise, I was billed R 1700 for this contract on a month-to-month basis on top of the monthly billing from my other contracts. I enquired at some point they corrected the bill I was owing with an amount of R4500. I even set my spend limit to zero to show that I cannot afford anything more than my credit limit. I did not get any form of communication stating that my package was upgraded to a month-to-month billing. I paid the outstanding amount after they corrected the bill. I then requested to cancel the contract but this month I got another top up which I did not ask for meaning I will be billed again month end. I called asking them to reverse the top- up since I did not sign up for it and I cannot afford but hey are telling about a 30 days' notice before they cancell a month-to-month contract that I did not sign up for. I just need them to take back the data they topped me up with on the 12th of August so I dont have to pay a bill I know nothing about month end. I still have that email informing me that I will automatically be upgraded to a similar plan.