Vodacom give me credit I do not want !

I went to Menlyn Vodacom, 14 January 2016 and took out a new contract. I specifically asked the sales person that I don't want a contract that is \open. I wanted to get a contract where I pay a monthly installment and when that runs out I can not be billed more.<br> <br> I took a U CHOOSE FLEXI 350 (TOP UP) contract that I chose in order to have the choice of topping up my own airtime and manage my airtime. <br> <br> I received a sms on 15 January 2016 stating a credit limit of R3001 has been set on my account. I never app**** for any credit and was not asked if I want the credit against my contract and also it was not explained to me that there will be a credit limit against my contract. I specifically chose the top up contract to manage and have control over my airtime on my own and don't have to worry about receiving a huge bill at the end of the month<br> <br> Take the credit limit immediately off against my contract as I have never app**** for it.<br> <br> Previously I was on prepaid