misleading consumers

I Took out a postpaid my giga 20 contract from cell C. The sales person, from cell C in Cape Gate did not inform me that the contract was a open line contract. According to my knowledge, the wifi would lose connection once I have used all of my data for the month. As per my contract, which clearly states that my debit order is supposed to be only R199 per month, and does not mention anything about a open contract. Today I got a call from the call centre to inform me that my balance from last month is R700, and my balance for this month is R1500 up to date, from the 1st, until today. As where I signed a contract for R199 per month and agreed to 5 gig anytime data, and 15 gig night owl data. The sales consultant did not mention anything about the contract being open and that it can exceed the amount that I agreed to. This is unacceptable Cell C, misleading your consumers, not training staff properly. I am disgusted, and so angry!Other service providers actually loads the amount of data to your sim, and once you have used it all, they will inform you, so you can buy a topup bundle. But cell c doesnt inform you when you have used your \agreed to"data amount. Pathetic!!!"""