Cell c contract outstanding

I have a contract with cell c for almost 4 years now with different contracts apparently a debit for December didn't go through and really don't understand how so hence money was there in my account then January they debit lower amount of which that not the monthly bill they suppose to debit.i made few calls and no one can explain exactly what happening hence I end up reversing the amount t thy debited on February. Till today I still don't get any break down of statement. Yesterday I received a call from collection and I kindly ask the lady to explain what this huge amount comes from I don't mind paying but I need clarification there. She transferred the call to other department and the lady I spoke to is Neo who also failed to explain .she was so impatience with me while I kept on asking her abt my statements amounts. She kept me waiting for 2 hours on a call I have prove of that coz I really fail to understand ain't we allowed to ask questions if we don't understand what's going on the the account?? I am very disappointed on this service am will to settle the amount I owe only there is a valid reason and right amount