Account cancelled but still being billed

i have been trying to cancel my interent/adsl account since November 2014. i went into westgate mall, jhb to cancel only the internet effective from 1 Feb which makes Jan the notice month. instructed the lady that the line should be cancelled by end on feb. she assured me that the internet would be cancelled.she told me to call 10210 anytime i have decided on thedate to cancel and it will be done. i asked my sister to call them for me in feb to cancel the line and they said i should send them an email they do not cancel over the phone.i sent the email on 3 Feb 2015 and there was no response for a long time. asked my sister to call for follow up since i was already out of the country she was told i should do that myself. which i did and was told it will be cancelled. when i asked about reversing the other charges the billing department consultant was not helpful and rude also claimed that the email was only received 3 weeks later which is the date they will work on to start the notice. it didnt make sense but i left it anyway. now I have received a bill again for MArch-april. this is ridiculous and honestly I am not even staying at that house anymore how do i pay for unused services