Stop sending me emails!

I am not a client of this business but somehow they've managed to get my email address and keep sending me notice of collections for other people. I've on numerous occasions informed them of such and i still get these emails! I've received an email stating:

''Good day

We acknowledge receipt of your email and your point is noted.

Kindly be advised that your email address will be removed from our system.

We do apologize for any inconvenience caused in this regard. Kind Regards Nasiphi Gxumisa E-Care Department Email *** Tel *** Direct Line *** Fax *** www.nudebt.co.za''

And guess what they are still sending me emails to this day!