Pestering emails

This company will pester you with their email offering training, u have emailed them so many times requesting that they must stop sending me their emails. They continue day by day. I phoned them to request that they remove me from their mailing list, continuously they continue flooding my mail. I am so stuck with this company that i don't know what to do any more. Can someone advise? Their emails does not have a "click to unsubscribe"