Vodacom - Terrible Service and still not sorted out.

Around May this year I received a phone call from a Vodacom consultant about my upgrade.. which was strange since I just upgraded a month before. No, this is for another number, one I don't know or have any knowledge off. So I found out that I have a data contract that has been running on my account for nearly 3 years. One I don't have and don't use. Long story short, it's for a data contract for a tablet, something I never received and have never used. Phoned Vodacom to get this cancelled immediately. They were very helpful to get the contact cancelled. But now.. I've been paying for this contact for 3 years! That is 36 months, and since it's Vodacom's mistake.. they owe me money. What a mission. I've been phoning and following up every week for the past at least 6 months with no success. Every time they inform me that the query have been escalated but up until today no one have been able to get this sorted or sort out my credit refund. Seriously, why is this so difficult? After this is sorted I'm done with Vodacom. They are just so expensive and data just disappears. Seriously bad service!!!