I think you're absolutely right. Called the number got a recording that says, "Thank you for calling. If you'd like to be placed on a do not call list for the number that called you, please press 1 now." The recording repeats itself endlessly and no one ever picks up. They never identify themselves. All that spells SCAM! Never push any numbers if you answer a call like this. It can be an acknowledgement of the call and acceptance of charges. Trust your instincts, they seem to serve you well.