Paying for data that am not getting

Took a contract with cell c that give R150 airtime and data for R35 however when I received the phone I called the call center asking them why the data its not loaded I was told that I must a separate sim for the data , but my question was why do I have to get another sim because firstly my phone only takes one sim those that mean I when I have to use data I need to take off the other sim from the phone the agent failed to answer me . I contacted the guy to offered me the contract by the name of Kgato he told me that the information was given its was incorrect he will escalate the matter than data will be loaded on the same sim he never came back to me I WhatsApp him again asking about the feedback still the was nothing well just decided to let it go , but what I don't like is that since I had the phone last year September they debit my account for the same data am not getting I don't mind the other amount being debited but why debit me for something am not getting all I want is for the debit to be stopped or sort out the data issue and be refunded accordantly.