Why bother phoning customers?

Two weeks ago I received a call from Zunaid explaining that my contract was due for an upgrade and as a valued client I was entitled to a discounted rate on the upgrade. He sent me an email confirming this and when I sent him an email to accept then all communications ground to a halt. I have tried calling him, emailing him and even sent a compliant to Cell C about this and from them I got the standard sms that my query will be dealt with within 24 - 48 hours ( so which is it 24 or 48?) I have still not received any feedback or resolution.<br> <br> For a company that claims to have such excellent customer service this proves the contrary.