Vitality Mobile Cancellation

Vitality mobile is now defunct. My contract with them ended on 21/12/2015. I decided to cancel my cancel my contract on 03/12/2015 to serve the 21 day notice. I was told to send an email to [Email Removed] . I sent the email and called every week until now. Today, 04/01/2016, my contract is still not cancelled and I am being taken from pillar to post (call cell C/call this number/call that number). I am fed-up. This is the final straw. If this treatment persists then I will have to take drastic action.