Dealer Services review: I have told them repeatedly not to call

I am extremely tired of receiving these calls. I understand how cold calling works, but when I have repeatedly told them to remove my number, it only seems to bring about more calls. Unfortunately, they always use a different calling number, which tells me this is just a scam to get money. In addition to the multiple phone numbers they use, the caller is always different - including many with heavy foreign accents.
Why is NOTHING ever done to prevent this!
I would like to answer the questions below, but they never tell you where they're located.
Check out these numbers 443-256-9710, 410-245-5280 and 667-201-7962...these are just 3 of the numbers used.