Unauthorised bulling

I too contract with Telkom back in 2014, my aacount was upto date, few month before my contract expires i lost my phone and decided to blacklist it but pay it till my contact expires, i phoned them to cancel and it was never canceled instead im paying something that im not using, i phoned so many times and i keep on getting case numbers but debit order is still goung through.

Case ********** 8 31 - Jan 2018 no one phoned for feedback **********

********** - No one responded

CASELOG001 - 13 Dec 2017 ********** - No Feedback and had to resent 16 Aug 2017