Vodacoms tactics pf exploiting their customers

I am sick and tired of vodacom and their poor service... since I changed from prepaid to contract with vodacom ive had payment problems with them... when you call their consultants they say one thing but then come month end they do something else... I changed my payment method last month from debit order to cash payment since I am no longer working and wasn't sure if my money would be in my account on my payment date and changed my payment date to month end instead of the 26 to avoid a late payment. I had made a payment on Saturday evening which is still pending on their side to reflect and this morning they debited my account as well. This is the second yime this happens to me. So I won't be getting my money back because they will rather credit my account and now I don't have money to pay my other account, should I reverse the money then they charge me an extra R100 next month although my account will be up to date... I don't know if vodacoms consultants are *********** or if this is just vodacoms way of making more money out of a person. I am done with this company and their expensive service that they bull**** a person with everytime... now they telling me I should have a reference for my call stating that I have requested for my payment method to be changed. But if I call from my nimbwr and they record every conversation then surely that recording shouldn't be that difficult to find since I got no sms or reference for my request and the consultant didn't inform me that I will get a reference number for my call.