the deactivation of my BIS

I have bought my black berry interne service last month on the 2nd of may then after few days it was deactivated,when I call the service provider they told me my case number will be resolved within 72hours it was never solved up untill I have decided to buy another BIS,when I call them again they told me I will get a refund which up until now I haven't got,when I call them they all tell me that their manager will call me by the end of the day and funny is I never got a call or even a miss call from them,as a Telkom mobile client I demad my refund before I move back to my MTN,so what they are doing to me is not what they promised to me to when I moved to their network,I also rate it. As the worst network ever