Capital Legacy "unpaid premium" despite cancellation

I cancelled my Capital Legacy policy in mid June. I was asked to send a cancellation form to an individual named Faeez after which the policy would be cancelled. I cancelled the debit with my bank and at the end of July received an sms and an email from Capital Legacy about an "unpaid premium". First of all, why are you still trying to debit from my account when I have already cancelled the policy? And secondly, after already clearly communicating with you about this cancellation, why am I still receiving email about an unpaid premium.