I am NOT an Iburst subscriber!!

I am getting emails from this company about migrating email. I have not had an account with Iburst for 3 years. Now they say I have selected a migration option and will be billed R50 once-off. At the end of the email is a tel number for queries. All I get there is a reference to their website so that I can register for email. ??????????? !!!!!!!!!!!!! and then a voice mail saying the person at the extension is not available! No wonder I ran away from Iburst 3 years ago. Complete chaos.