No response on Query of Broken Phone

Hi - I received my upgraded phone in Oct 2015 - stopped working in mid-November 2015. I reported this to Cell C on the 24/11/2015 Ref no - PRE 688703 - to date we have had no response from Cell C in picking up the phone for repairs. I emailed on the 07/12/2015 - still nothing. Please can you confirm how long does it take to pick up a phone for repairs after all I was told by your employee it would be 5-7 days. It is now almost a month so I am paying for a service that I am not getting. Should I terminate a contract that I have had for 12 years...as the service rendered has been pathetic.