No Joy at all

I took a cellphone contract with them which comes with 500mb of data, I received my phone on Tuesday and Im happy about it,but the data is not connecting I have called them several times and I get told one thing to switch on and of my phone ,and today I was told to call vodacom which i did but still I didn't get any assistance.So what do I do with this sim card thats not working, do I have to buy data of which I was promised to get data monthly.im so not happy and I dont know what to do now.