Not cancelling my contract as requested!!!

I sent an email to ********** on the 16th of November 2017 requesting cancellation of a contract that I no longer require. I have followed up several times with the call center and even forwarded my cancellation to one of your call center agents on the 28th of December who assured me the contract would be cancelled immediately and I would not be billed. I was still billed and I can see on the telkom website that my account is still active and scheduled for billing end of January. Such incompetence is really annoying especially when no one bothers to give feedback to the customer! Can someone look into this and cancel this contract!