I wish I could help but with the difficulty of tracing people and signal groups that you are talking to, that is somewhat hopeless to find them.
Sorry for that bad experience but in the first place, if you have read in the forum talking about signal groups, you will find that they can't be trusted. Unfortunately, it is too late for that knowing that you already fall into the hands of scammers.
If I were, stop chasing those people and forget about it because no matter what you do, you can't take your money back. It could be sad but this is the reality of trusting strangers online, we are not sure if they will give us the help we want (or just scam us).