debited incorrectly and no feedback

In aug 2015 vodacom discontinued my contract and migrated me from a top-up 500 to a flexi 500. They charged me an additional R336 for subsidy fee incorrectly. They admitted it was a mistake on their side. Simon Maleho confirmed via sms that the validity of the credit amount will be processed. Later on they confirmed the amount will be refunded and again i was told that the amount will not be refunded but will be used as credit for the following month. This month i was debited incorrectly again. When i phoned again to query this... no-one knew what was going on. I was transferred 5 times between departments. I get excuses like... the system is down... we don't deal with accounts... you need to contact migrations... we don't have a migrations department... i am sick and tired of this bad service. And after a month, my problem is still not solved.