No service provided, still getting billed

I filled in sent in a cancellation form on the 28th of April. My contract(8ta) had expired in Feb and I was left only paying for the data (R99). I got an email on the same day saying it would take 21 business days. And 4 days later on the 2nd of may I was debited R99. I'm not sure if that was to pay for April or for may but I didn't care because I expected that to be my last payment especially since I wasn't given/ nor did I use any data during the month of May and believed it was all sorted out. On the 4th of June (certainly over 21 business days later) I get a CASE NUMBER ( ********** 2), When I'm expecting to get confirmation that I was migrated back to prepaid and my contract was cancelled. At this time my SIM card is still receiving no data/services, I know this because I tried goggling something almost every other day on my commute but to no avail and since my bank account is empty (life of a student) I don't pay the case number any mind not realising the failed attempted debits from telkom mobile.

Fast forward to the end of July and I'm able to afford some data due to doing an internship so I purchase directly from my banking app onto my sim because my SIM card hasn't had any data on it since April. I wouldn't have bought data if it did as I only ever use that data on this sim on my commute home (where there's wifi) from work (where there's wifi) or to University(where there's wifi).

I had loaded about 500mb of data and in a week it had expired and I thought maybe I had made some mistake and loaded a further 500mb only to find out that my number had been blocked and that I owed over R500 !!! I phoned about 3 times and got absolutely nowhere with the customer service. All I was told at every turn is that there's nothing I can do but pay the outstanding amount.

How can I owe money when I haven't been getting the service?? And even if I was getting data (which I was not because I checked countless times). Telkom mobile keeps trying to debit me monthly and I keep blocking them and every month the balance goes up over R100!!! It's now at over R600 and for what reason?? Does no one competent work at Telkom?? I can't just give away my money away because that's what I would be doing as I'm being charged for a service never provided!!