Bad Account Management Infrastructure!

I have a data contract with Cell C and didnt realise my August debit didnt go off for some reason as I always ensure I have funds to pay my account. Nevertheless I lost my sim and got a new one from a Cell C store. When calling in to do the sim swop the consultant told me I was in arrears! I was shocked by this and then asked why I was not notified. I was apparently called in the data sim which baffles me! I gave numerous contact numbers and main contact which is my mobile number! not data sim number! What kind of Credit Controlling does Cell C do with such inefficiencies! I am appalled that one number which I did not give as a main contact was used. Theres various methods one should use to contact customers! All given contact numbers, email and so on! None of these were used then I was told by the agent that I cannot be assisted. Furthermore I was told I will receive a call back and have a manager attend to my query upon my insistence - No call to date - Does your clients mean this little to you! I am utterly disgusted by your bad service! Now I cannot access my data due to your Accounts departments incompetence! I want this resolved and by management - not call centre agents that read off a script repeating the same garbage over and over! you have my primary contact number! USE IT !