How can I make these spamming sales calls go away?

One tactic I've used successfully is to change the outgoing message on voicemail to begin with a recording of that tone the phone company uses to indicate a disconnected number. I have it repeat once or twice and then come in after a pause to say "if you're not a spam/sales call and are trying to reach me (I don't give my name in case its a live operator taking notes!), leave a message." I've eliminated nearly every one of these rogue callers, and I've had some pretty strange ones over the years (this is a land line, which might explain why it gets a lot of calls). It might not work as well for live operators, but anything that is dialed robotically or by computer I think will listen for that tone and act accordingly to delete the number from its database automagically. At least that's what I want to believe!! I only had one robo call that I finally had to catch and use its "press 5 to stop receiving these calls" to end their pestering.

Just let the calls go to voicemail. Don't waste your time trying to explain anything to these people.

But most people are helpful and can help you track down how they got your number To the contrary, every single time I've tried to engage these people on anything other than the script they've been handed, they simply hang up.

Solomon has good advice (heh) if that's the way you want to go about it. I've found that "against my religion" is a surprisingly useful tactic in removing myself as a Prospect. When I had to explain to my cable company, for the tenth time, that I had no interest in their TV or phone service I eventually told them that I could not watch television because of my religion. They didn't call back again. So you could always try "I did not fill out the forms and taking out loans is against my religion." Calling you costs them money, and if you can find a way to make it clear to them that they will be religiously offending you by trying to sell you the product (which you will never buy), there's a strategy.

We had a bunch of calls stop when... well. I had one of these calls on the line, was trying to get to an operator. She picked up just at the precise moment one of the our cats jumped onto my sleeping roommate's chest, causing her to let out the most blood-curdling scream I have ever heard before or since (and my roommates are horror movie fans and I have heard a lot of them). There was a moment of silence, they hung up and the number of spammy calls dropped to about half of what they were before. This may be hard to orchestrate, I admit.

Next time you get a call, explain your situation and ask how they got that number. If they try to dodge and say that you filled out something saying you asked for it, ask for a supervisor and tell them your story again and ask how they got the number. But most people are helpful and can help you track down how they got your number - whether it's from some list or something - and then you can find out how to contact the people who own that list, and ask THEM how they got your number. Also you can tell them to take it off. You may get some more calls from people who have already gotten your number, but at least you've gotten at the root of where they got it.

I've had success in the past with telling the company in question that I'm completely unsuitable for their product. If I get calls offering me new windows, as is common in the UK, I tell the person on the phone that I live in a council house. Council houses are paid for by the local government, and there is no chance whatsoever that the local government will pay for me to have new windows. A few times of doing this and the calls from various companies stopped. I'd suggest telling people who offer you a mortgage or loan that you're bankrupt or in some other financial dire strait, and therefore are suddenly a very unattractive prospect to them.

I usually don't answer a phone call from a number I don't recognize. I use Google Voice from my voicemail and it is easy to permanently block unwanted callers. If they don't leave a message I can Google the number and figure out that it is from an unwanted solicitor too.

they simply hang up Yup. A lot of times, when they know they're doing something illegal, they won't even tell you the real name of the company. I was getting daily calls from "Carpet" for a while -- that's what the person said the name of the company was.