Telkom unfair overcharge me.

As a person who uses data bundles a lot I was attracted by Telkom reasonable low premiums on Facebook advert. As I work in the security industry I get very low salary. I saw R269 per month will be good for me. I think it was August. My 1st month was okay, but my 2nd month they changed 1st the number of data bundles and the amount they debited was R484. Following was the same I checked my Capitec app to see who takes this R484 and I found a company name which I didn't know. Next day October 2024 I went to Capitec they also didn't know, I then reversed the money and blocked them. Later that day I received an sms telling me to pay Telkom R1125 or I call. I did call them only to find they are Telkom lawyers. I ask them why are they taking more than their client and my contract agreement, they said I missed October payment, I was like how? Because I told Telkom agent when is my salary going in and when they should debit. And they said I pay that much as it is their fee they charge their client, and I ask why are they debiting to me and not their client. As I write now I am blacklisted and I owe Telkom R2200+. I find that as a ******* as I can't pay that much for their agents incompetence. Please help.