Telkom Debiting me even though i am no longer using their service

Hi there

I have been debited this month for your service even though i am no longer a customer of yours. I had cancelled my service with you over two months ago and i see that i am still being debited for a service i am no longer using. Please can this be resolved ASAP and cancel the debit order you keep taking from me. Ref:Telkommobi ********** 080 R463

I look forward to your reply.