Requested mtn to cancel my contract since June still not done

Had called MTN couple of times to cancel my contract and the last time I called to tell them that, that was my last call to them. Now they have loaded my phone with data and bill amount. Is there a number that I can call to complain. I am not going to use this data so I have told them.

With my second contract I requested for an upgrade its a month later, they uploaded my phone with data and airtime. I called, told them that I cannot pay for data i did not request however they tell me that I must pay. I will not pay for something I did not request due to their incompetence.

Please if there is a number I can call to lodge a complaint please do help.