Billed after cancellation

I went into the Paarl telkom branch on 11 March 2015 and cancelled my ADSL package (reference A***0). I was told that as I had to give a month notice, my ADSL package will be discontinued on 11 April 2015. On 9 April 2015 I received my bill for 09 April- 08 May , and by 13 April 2015 our ADSL was still active. I phoned telkom on 13 April 2015 and lodged a complaint (reference number ***3) and was told that it will take 72 hours maximum to sort it out and cancel my ADSL. It still has not been sorted out and now my line migration was cancelled because telkom cannot sort themselves out. I do not know how much more in advance I must cancel my subscription, and definitely hope I am not expected to still pay the April/May bill. Very unhappy.