Cell C Nite Data vs Anytime Data usage - Poor Query Handling and billing

My Cell C contract phone is depleting my Anytime Data during Nite Data periods. (Cell C users, please check your data usage)

I have logged this query with Cell C. They claim to have tried to get a hold of me but could not. My phone is always on and I receive calls all through the day. But Cell C claim I cannot be reached. (Perhaps this is a reflection of their network?) I eventually called them on 135 (Customer Service). The agent heard my query and said this is a technical issue and transferred me. Technical said this is a Customer Service issue and transferred me back. The next Customer Service agent said this is a Back Office issue but that she could not transfer me because no one can be transferred to Back Office (whatever that means). The best she could do was log the call and someone will call me back within 24 hours. Its now been 96 hours and no call. Its been over a week since my initial query was logged. I have spent R1000 on data and my problem still persists! I have been a loyal Cell C contract holder ever since Cell C opened shop in 2001 and this is the level of service long standing customers receive. Perhaps its time for a change?