I suspect it's Future Films too. They've called me before with numbers from all over the country. The films are good if you have young children but the company is obnoxious. My kids are 24 & 22 now, my phone number changed years ago, is unlisted and yet they still managed to find me. Once found again, I've been harrassed daily with phone calls from them.
This is one of those situations where you are going to have to spend a few dollars. Write a letter telling them not to contact you, by any number they may wish to use. Send it registered mail, with return. Make SURE you clearly state in your letter that you now have NO business relation with them, and will report their calls, as well as legal action against them. If legal in your State you may want to start recording your phone calls. Don't forget to tell them that. I'm sorry you have to do this, but they will always use the excuse that you bought off them (business relationship) until you tell them otherwise. I used to get letters from (a well know publishing prize company) that sent my mother letters years after she died.