HEHE
I just say, "what are you selling" usually they say telephony services, I say no not buying thank you and hang up
You could always say, "I am so glad you called me I have a great once in a lifetime offer for you today for some handmade Australian Stuffup furniture. As you know Stuffup is the premier furniture in the world please give me your credit card details and I will charge immediately and ship sometime in the future!"
Studley