You mentioned 2 exchanges I've never heard of, did the signal channel owner just point you to that exchanges? If so, try withdrawing your funds to ensure that you areb't being fooled. Beware of something free.
Yes, they are actually the one who choose on which exchanges we will trade. In addition to that, I noticed that all coins they were asking us to buy/sell are not presence in other known platforms like Binance.
I believe by now you would've realized it's a typical Pump and Dump group and you should understand the implication of what you're setting yourself up for. Bump and Dump groups are like that. They dictate what cryptos you buy and on what exchange. Even when sometimes the crypto in question is listed on more than one exchange, the P&D group is likely to point out it should be traded on a particular exchange. Another thing is that the owner(s) of that group is(are) more likely to load up any crypto they're making calls on first before making it public. That way they secure themselves first and stand at less risk. In all this, those who follow such group are the pawns.