Overcharged

My cell package was upgrade to an higher package without by somebody in Vodacom. I never ask for this or gave approval. I logged a query on 9 Feb 2016 and received a ref no GM922-23URM. On 10 Feb 2016 my cell package changed back to the original. On 12 Feb 2016 I logged a query again about the refund of my overcharged amount , ref no GMC2Q-QTTBR. As I received no response yet I phoned again today, 24 Feb 2016, and only got promises that somebody will phone me but the person cannot say when. Next week is payment time again.