Last October I started a company in France. The French government kindly supplied my details to various companies without me asking. I suspect this happened because information about companies is a public record and certain marketing-savvy companies slurped up my information and sent my 'useful' junk mail: catalogs for office equipment for example.
One of the companies that felt the sudden urge to write to me was Dell. For a while I owned Dell computers and for various reasons (mostly to do with they terrible support for small business and their weird 'you need to buy Dell racks for your gear') I stopped buying anything from them.
So as each piece of junk mail came in I would unsubscribe. Sometimes this was a phone call, sometimes a fax and sometimes it was necessary to return the item with 'Désinscription' or similar written on it.
And it worked great, except for Dell.
For 10 months I've tried to unsubscribe.
I've emailed them at firstname.lastname@example.org as requested. I've faxed them on 0825 004 682 as they also suggest and I've mailed them at Koba D/03-F, ZI de Chevreuil, F-60490 Ressons Sur Metz. And still their junk keeps coming.