Airtime deducted for unauthorised subscription

Money has been deducted from my airtime for a Lotto subscription that I did not authorise. I've been trying to sort it out via your Facebook page with no success.

1. I have cancelled the subscription 2. I wish to be refunded for the airtime used

I have already been told the following which obviously has not sorted out the problem:

1. To cancel it (I did this before contacting you) 2. "The system does not show any activations." (Yes, as I already canceled it!) 3. "You will have to contact them directly to find out how you were subscribed." (Contact whom? I didn't authorise it, how would I know who to contact?) 3. "We don't have statements/invoices for prepaid accounts."

Please refer this to someone who can actually sort this out.