Telkom *****ing my money

I have a month TO MONTH Telkom adsl data package. On the 19th of January I called the call centre in order to cancel my data package only. I was asked to send a form together with a copy of my ID. I did so the same day and received an e-mail confirming that my e-mail was received I called back on the 17th of Feb to make sure everything is now cancelled. I was told they never received my form. My ONLY alternative was to resend the form with I did the same day. I went into the Telkom store at canal walk today and low and behold my data package is still not cancelled. All the while Telkom happily debits my account. PLEASE TELL ME WHAT ELSE I HAVE TO DO TO GET YOU TO STOP TAKING MY MONEY FOR A SERVICE THAT I HAVE CANCELLED??