Poor service

Hi.Eversince I opened a contract with Vodacom I received phone calls and text messages asking about some other person which was not me .But my real problem is I activated a recurring bundle of R525 and then when I checked my invoice my totals where R2400 for expenses of video tickets whatsapp bundles minutes which I never authorized..So I called Vodacom customer service and they told me it done from my another sim so I believed it and I told them to cancel every bundle and the agent said they will..So I checked my statement again last week and I saw my account was still building up and I called vodacom again they said they can't cancel the "purchases" before paying the debit order.I did not request for any additional recurring bundles but only the 20gig bundles.I don't know how it happened but it needs to be sorted out cause I cannot pay that amount.