Bad service delivery from Vodacom SA

I phoned Vodacom several times and explained that money was paid into my account wrongly and would like to be refunded, I send the paperwork what they requested, they said it would take 5-7 days, nothing happened. I phoned again, no claim were entered into the system, I requested again to be refunded today, now after two weeks already and sending the email again, and really now I wonder if Vodacom will refund me the money that they owe me. If we owe money, we have to pay now or the cellphone will be cut, but if the service provider owe me/ you money, you need to send proof, several times and at the end they will still have a problem, so tell me, is this how we are to be treated when you overpaid you account and struggle to get your R2000 back?!