"You've been calling us, well, semi-regularly, and I'd like you to stop, please."
"But you gave me your number."
"My girlfriend did. At any rate, we'd like you to stop calling."
"Then why did she give my your number? That's pretty immature."
"She was interested. She isn't any more. Please stop calling."
"Fine. I wouldn't want to deal with you anyways."
I called him a twit and hung up.
So. If you're looking for a financial advisor who isn't, well, an ass, I'd suggest looking elsewhere.
I was very careful with my tone of voice to not be rude, condescending, or otherwise offensive, right up until the final word "twit". He was given our number; he had the legal right to call us -- until I asked him to stop, with my first sentence.
I cannot fathom why he, and other salescritters, try to argue with such requests to stop calling. It's not like they're going to change my mind.