MTN ****** Me - Refund!!

I cancelled my MTN contract on time & paid the outstanding monies in order to get it terminated. I was reassured by a Customer Care agent that it was cancelled & I even received an SMS confirming this. Then a week later I received data which I should not have as the contract was cancelled. I then queried this & it was advised that my contract was not actively cancelled on the system & that it will be cancelled & my data would disappear. To my surprise, I received an invoice a few days later for R187.88. After numerous of follow ups on Facebook, email & telephone, all I was told that my query was escalated & till today absolutely nothing has been resolved. WOW so pathetic MTN, I demand a refund as this is *******! Can't even attend to a simple query. I am so glad that I am done with this contract. You guys are utterly unprofessional to say the least! My constant follow ups done absolutely nothing. Thanks for taking a used to be loyal customer for a fool.