Unhappy Telkom customer - Poor customer service

I contacted Telkom on the 29th July 2021 to cancel a 1TB LTE contract I have with them with and spoke to one of their consultants Zimkhitha Ntombana. As they do they convinced me to not cancel the contract but to rather migrate it to a lower package and therefor not to lose the number etc. I decided to keep it and migrate to a 20GB Wireless Promo deal which they advertised as 40GB daytime and 40GB nightime data for R199 p/m. Zimkhitha then also confirmed via telephone and e-mail the migration would take place from 1 Aug 2021 and my debit order at the end of Aug would be R199 for the number in question. On the 25th of August my debit order was deducted and once again I was billed R999 for a TB worth of data. When I contacted Telkom they advised I'm billed in arrears so that would be the charge for July which is a lie as it states on the invoice that the billing for 1 - 31 Aug is due on the 31st of August. I decided not to argue their mistake however I did call them again to advise of the error and asked that they make sure the number is switched to the plan I requested for R199 however they sent through my September invoice to be deducted on the 25th of September and yet again they are billing me R999.00 for the month. I have since called again on mulitple occassions asking that they rectify the issue as I refuse to pay R999.00 at the end of September. Zimkhitha however advised me today that I now have to pay R500 for 5GB of data used (of a 1TB package!) for the month of September which is apparently a favour being given to me for a mistake on Telkom's side. So not only did I have to pay R999.00 for their mistake in August but they now expect me to pay R500 for 5GB data usage in September. I have 3 contracts with Telkom which I've had for 3 - 4 years now and this is the kind of treatmeant they provide to customers. On top of this the matter has supposedly been escalated to her manager Maxime Rustoss who would contact me before 5pm today but I am still to hear anything. I demand for this matter to be rectified and will not pay R999.00 again. Furthermore I would now also like my account to be credited with the R799.00 as my bill for August was supposed to be R199.00 and not R999.00. Whoever picks up this complaint please have a look at the usage on that number as it did not even come close to the allocated data usage of 40GB daytime data it was supposed to have been on from August. Reference number ***A