Contract Dispute

As my contract was to expire in June 2017, I cancelled the Vodacom Contract with the intention to migrating to Telkom. I wanted the Unlimited Offer from Telkom for R999/month - this is unlimited calls, sms and data. A gentleman from Vodacom (Mondli Galawe in Retentions Dept in Randburg) came back with the a similar offer of R1000/month - unlimited calls, sms and 20gig. I accepted this offer. Since 1st July, I have been Invoiced R 1,597.76/month. After countless calls Mondli informed me that a Credit has been passed. With another to follow. Thereafter I will be Invoiced the R 1,000.00 every month. To date, absolutely nothing has been done and I have to pay the Invoiced amount or be cut off! I have left numerous messaghes for both Mondli & his Supervisor (Magdalene). I am still waiting for a call back. I have the emails for proof that I have this Contract in place (even though I have never signed ANYTHING).