Cancellation of line still being billed 2 months later

I downloaded and filled in the line cancellation form in December and emailed it twice on 2 separate occasions to the address they provided and I am still being billed for this month. I then went to the Telkom branch at the Mall at Reds in Centurion where I initially opened the account and Amanda simply phoned the billing department and wanted me to speak to them. The billing department was already closed. The first issue is why is Telkom still billing me for a line that should have been closed and why can't the staff at the Telkom outlets assist their customers. I feel that I should not be paying for a line that I requested be cancelled due to Telkom's incompetence. Can Telkom sort this issue out immediately please.