Sent an email to the provider:
Hello, I received a call from one of your Colorado customers from phone number (720) 403-8550 on my cellular number (xxx) xxx-xxxx, which has been in the do-not-call-list since July 2013.
I believe three years is enough for telemarketers to adhere to the Federal Trade Commission's Telemarketing Sales Rule.
I am not alone receiving theses calls: http://800notes.com/Phone.aspx/1-720-403-8550
Please take action with your customer. It puts your company in a bad light.