Vodacom please help CellC with their service

After numerous call to CellC's retentions department and their contract cancellations, the procedure and cost implications for buying out a contract were still unclear. So on 10 November I sent an email and was happy with the quick response giving an incident no: *** and promising a call back in 24-48 hours. On Wednesday they called but as I was unable to take the call, they said they would call back in an hour. There has been no return call since then, despite persistent emails to the same address I originally used, replies to their send address and to the retentions email - NO RESPONSE. Today in frustration, I called customer service again - the incident no has been cleared and when I was transferred to contract cancellations, they cannot help me, as they don't deal with email queries! When I went through the same query with my Vodacom contract recently, they were so professional that I extended it for 24 months.