Voice- and ADSL line cancelled, but still being billed

My Landline and ADSL was requested for cancellation on 9 April. It was FINALLY cancelled on 9 July (SMS confirmation was sent). However, I am still receiving an invoice from Telkom for the ADSL every single month to the amount of R431. My reference numbers for BOTH cancellations are ********** 3 and ********** 2. I received confirmation that BOTH was cancelled in two seperate SMS's on 9 July.