Here is the FTC FAQ page which the DNC site repeatedly invited you all to read before you registered your numbers. See items 28 through 32.
Q&A: The National Do Not Call Registry
To halt charity calls you must revoke permission to call yourself. You are likely to find the calls are placed by a commercial fundraiser, such as Associated Community Services, Dial America, Donor Services Group, Harris, InfoCision, MDS, and TeleFund. As commercial entities, these hired call centers are expected to honor an internal no-call list and add any number upon request. Break that order, the FTC declares, and ''the telemarketer may be subject to a fine of up to $16,000.'' They are also covered to a point by other regulations for telepests, so you can kvetch about abandoned calls, bot calls to mobile phones, and so on.
In a comment from Jan 2012 linked below, find the simple steps I took to rid myself of a major pain boiler room by politely rubbing its face in federal laws. You will note that I never rely on verbal cease-communication demands.