vodacom lying to customers to get sales

On 18 december 2019 an agent from vodacom (which I later found out was actually one of their external companies they use)called me offering to increase my data on my contract (at no extra cost). At the time I specifically asked if they where going to increase my monthly contract price, to which the said no. End of jan 2020 I get my bill and it is almost R200 rand more and this is where my trouble starts. After calling there customer care and being transfered to various incorrect departments, I finally get to the correct department where they tell I did a migration. When I ask to listen to the recording of where I gave permission they tell me I need to go instore to get the recording. I go to canal walk vodashop and ask to speak to the manager who does not want to give her name(Stephanie I later heard someone call her) she tells me no they don't have the facility to to let me hear the recording. I then again call the call center to which I am again told to go in store. Im fuming at this point. I go to Kenilworth centre vodashop and I am given the same line sorry you have to do it over the phone, at which point I lose my **** with the salesperson. I then go back to another branch and I am told off the record that is vodacom's Modus operandi, the sign people up about lying about and out of every 10 people if only 3 complains that still have 7 more new sales (70 %) , which makes sense as to why they don't want me to hear the recording.