Best way to handle unwanted telemarketers?

For the past few weeks I've received at least 3 calls daily from the same telemarketing company. This company is trying to exchange $100 gift cards for $2.95 shipping/handling. I've asked multiple times to be placed on the Do Not Call list. When I mentioned this to the representative today, I was informed in a very arrogant tone, "Oh sir, we are a very large company with phone numbers from every state. That isn't going to work." The company refuses to disclose its name.

Any clever suggestions to report and/or combat this issue? I've filed multiple FCC complaints, but I'm not confident this will lead to a resolution.