Wrong Bill

I have a ADSL contract since 2017, when my contract ended I continued with month to month, in March 2020 I received an SMS that there was an upgrate in my area of moving to wireless, I responded to the SMS, then a number that starts with 01288 kept on calling until I spoke to a lady who told me that I will be paying R799 but I said I don't want the voice so she said she will remove it and I will end up paying R750, but all these months my statement has been reading I am on a R899 contract, I have been speaking to different people who have been giving REF and saying they will log a call to get this sorted out, I was refunded when disputed the amount but I want my billing amount to be what was agreed upon, I am so annoyed by this as it's dragged for sooooo long, list of REFs ***2, ***5, ***2, ***6