3.5 BTC is pretty big and how lucky that scammers to get it. Scammers will use different tricks just to catch their prey and the sad thing is that you are one of those prey. It is really sad and we felt it and this is one of the disadvantages of crypto, you can't recover it anymore. Even though a lot of similar things happening around but then, many were still investing Bitcoin and ain't give them a big reason to quite. They are learning their past bad experience and that quitting is not a way to get it back.