MTN a law unto themselves!!

I cancel a month to month contract mid December 2015 in store. I was told in 30 days it would be cancelled. To date the retentions department (who one cannot phone, only e-mail) has blatantly ignored my request to cancel this contract although it is well within my right to do so.<br> I have just phoned customer care Again! and nothing has been put on the system. I now have to wait another 3 days and then I must follow up. ***<br> How does one fight theses dumb corporate giants.