Vodacom billing and After sales service is concerning

I truly love the connectivity that vodacom offers. But their after sales is so disappointing. In May I had a non payment and they reversed the original invoice and added an extra charge, which is fine and I went in store to pay this in June. The June payment was meant to go off as a single payment since the May is no longer applicable however they decided to load 2 invoices for the month of June. They do not wish to confirm why 2 invoices were loaded for the month of June and want me to pay both invoices. I spoke to a consultant who was kind enough to at least send me the statement so I can have a look at what was actually happening. In all instances, not even a single consultant requested my bank statement to confirm any of the payments. Called in the entire week and went to the vodashop (unfortunately the voda store agent couldn't assist because it was the weekend and she needed to speak to billings on my behalf. I don't mind that) but no one else is actually willing to help me.