Ineffectiveness and inefficiency with procedures in place at Vodacom

I don’t rate Vodacom at all. First of all they claim I never notified them of cancelling my contract, which has now ended and are still allocating me data and billing me. Why when the contract has ended? Claiming it on some we never received your request. Secondly, these people have been in the past 24months/begin of the contract billing me more, which I assumed they could be billing my advances twice. I called them of this and as per usual they did not action on it, then they have the energy to say I must settle my bill then they will give me airtime back worth the over billing they have been making. How when you took money from me? Why must it come back as airtime cause you didn’t take airtime from me? Get your processes running properly and do your work! Now I’m getting billed cause you didn’t do your work?