Contract expired in August and I still get billed

I had a contract with MTN and which expired in MTN. I called 808 theh could not assist me to cancel my contract. Said nothing picks up with my ID number. I drove all the way to Metlife branch to cancel it. The lady Jillian helped me. This is the same lady i took out my contracr initially. She checked on the pc and couldnt pick up anything with my ID. I told her she opened contract initially for me. She recgonise me then. But still could not pick anytho g up. I still convertated my prepaid sim to a data contract sim for R169 for 3G data a month. She said i should give her the sim card no. which I want to cancel. I do not know the number at all. Was a laptop with ****le oaxkage I had. She said I should put that simcard in my cellphone and call 808 if i would like to keep that number on prepaid. Which I did not do because I didnt want the number anymore. I qeuried my debit order of this month which was R497. Called 808. She ligged a query because I was billed twice for my new contract which i got in July. 169 x 2 and then only I heard im Paying for the laptop package still, because I did not cancel it and i hav to give 30 days notice now ! I did my part I am not paying for 2 contracts