DIRECTAXIS ARE THE ABSOLUTE PITS

I have given up on this company and their spam emails - i get around 5 or 6 per week - i have asked at least 50 times to be taken off their mailing list and ignored - i have phoned and insisted they delete my details yet they still spam me on a regular basis- i have blocked the emails but they appear to have about 10 000 different email addresses from which they send their junk - how do i sort this out