robbing money

I have paid my arrears amount at the Vodacom store they used the reference number belonging to my dad. I called Vodacom accounts and was helped by Solly Maredi, I emailed my proof of payment directly to him and he went to his supervisor to approve the proof of payment to be moved to my account. he said it is fixed. Coming month end my bill was so high because the arrears amount that he said was correctly allocated was not allocated at all!! I have to pay this month again a high amount because of his incompetence, I even emailed him directly with no response!!