Selling lies, and do not update their systems as per clients request

My cell phone contract was taken out in Dec 2016. I received a call in April 2017 due to me being a loyal customer, I'm being offered a WIFI router at 2 or 5GB for R149 monthly, I still requested a 0 limit once we are out of data. I was promised this will be done, clearly a sale is being pushed. I start receiving statements with ridiculous amounts, I went into the branch where I was told, I have a R500 spending limit, and then I'm being billed after the R500. my understanding was that I could call Telkom to Telkom which was free, however a agent calls me stating I must select 5 Telkom number for family and friends at R49, this is a lie. I'm billed for Telkom's error, and they will re-imburse me. they are *****, if you don't look at your statements you will be *****ed, this month I received my statement and a Mr Arendse, wow!!