Regret this bad deal

On 21/01/2019 someone phone me from cell c.she was selling a valentines special,20gb for R149.to make a long story short.what she told me was that I won't pay in January,because it will only be pro rata data which I will pay end February.so I must myself phone customer care to put a limit on the sim card,cause she can't do it on her side.I told her I will only use the sim in a router so I don't have a phone to put that sim in.apparently she couldn't help with that.I asked her what if I no longer want the sim,unhappy and want to cancel?so she told me within 7 days I can send back the sim but I will be liable for courier fees,and if I send the sim back within 21days I won't be liable for courier fees,and that I must pay for the data that I used that month and only than they can cancel the contract.I will receive the sim in 5days.I told her I don't have money for the sim because I have an contract with mtn also for data.she kept on and on,she even hold the line for almost an hour cause I was busy with something.too desperate for selling but poor service.I received sim on the 25 January,activated the sim on 28/29 January.I only phone customer care onda 5/6 February to set limit,cause I never in a million years thought the data would be like finish ...Only on the 10/11 February I realize that I couldn't go online.so only when I put the sim in a phone I saw that there's no day to day data but only night,and that the bill is R713,90.totaly not what I bugdet for.I immediately phone them so they told me I didn't set the limit as soon as I got the sim and that I'm liable for march also.which I also questioned cause it's not like I had the sim for a month!I was so upset and just wanted this contract cancel,which they obviously didn't want to.I phoned them 4-5 times within that 21 days,but each agent wanted to give me extra data.finally someone said she's gonna put in a request for their manager's to listen to the recording of that day of "signing" the contract over the phone.they got back to me almost 2 weeks and said that the person selling me the deal told me that I must set an limit.so my question was and still is where is the rest of the almost 2 hours of conversation?they couldn't answer,cause than they will hear what was really said that day.I want my name to be cleared cause I payed them,they deducted the payment of R713,90 end March.and after that they still deducted money and I keep on reversing cause according to me this bad deal is over.there was a nudebt on my status at bank,so cell c don't have all their facts straight but is handing me over!why are they saying calls are recorded when they don't make use of that recordings afterwards.I really regret taking out this deal.I never take out deals onda phone anyway,so I don't know why that day!I just want this contract to be cancel and my name to be cleared please.Agents name of that day is Happy.