Cell C should treat me fair also their honest customer

Good morning I have a problem with cell c regarding my cellphone contracts and I have been their honest customer since 2014 but now they are really not giving me a better service, they changed the day of taking their money without my concern and after then I had to send money by myself, after then,they say I owe them but after calling them I raised my issue, they said they will resolve the issue, even now they still resolving it since February,last week I called they requested me for the proof of payments which I did but still they still say I owe them, last week they took money from my bank, I reversed it and call them, they say I'm going to pay penalties, for what I don't know because I have been sending them their money and the proof, now my phones are barred, I can't call, send sms or check my balance, this is really not fair