Unfortunately as annoying as this may be, these calls are probably not a violation of the National DNC List.
https://www.donotcall.gov/faq/faqbusiness.aspx#whoWho May or May Not Call?
Who is covered by the National Do Not Call Registry?
The National Do Not Call Registry applies to any plan, program, or campaign to sell goods or services through interstate phone calls. This includes telemarketers who solicit consumers, often on behalf of third party sellers. It also includes sellers who provide, offer to provide, or arrange to provide goods or services to consumers in exchange for payment.
The National Do Not Call Registry does not limit calls by political organizations, charities, or telephone surveyors.
What about an established business relationship?
A telemarketer or seller may call a consumer with whom it has an established business relationship for up to 18 months after the consumer's last purchase, delivery, or payment - even if the consumer's number is on the National Do Not Call Registry. In addition, a company may call a consumer for up to three months after the consumer makes an inquiry or submits an application to the company. And if a consumer has given a company written permission, the company may call even if the consumer's number is on the National Do Not Call Registry.
One caveat: if a consumer asks a company not to call, the company may not call, even if there is an established business relationship. Indeed, a company may not call a consumer - regardless of whether the consumer's number is on the registry - if the consumer has asked to be put on the company's own do not call list.