DEBITED INCORRECTLY AND DEBITED AFTER CANCELLATION

I cancelled my contract after being debited R500 instead of R99. Their excuse for this amount is unacceptable and they could not provide me with the detail I required. I then cancelled in March/April 2017 and are still being debited as at this day. I have send numerous emails and complaints to Yellowdata whereafter they respond that they have a system glitch. I have not yet reversed any of the debits as I do not like negativity on my statement. After this experience I do not even trust those companie that really are legit.