Best thing to do is ignore and not reply and report and block them because if you talk to them they will see you as easy target and keep bothering you.
Some knowledgeable people still talk to them, only to piss them off. I guess this is one of the best revenge that we can give to them. Maybe they are now the ones that will block us. Imagine if many people are like this, I think time will come that they will think twice if they will still do such an action

.
This is not just problem on Telegram but on all messaging apps so staying alert and cutting off contact right away is safest way to protect yourself.
Yeah, scammers are everywhere but Telegram only got popular because it is decentralized, so you can get a message from random people directly, not like to others where it can usually fall off in the spam folder or message request first. Not all are techy enough to go on these sections, so the chance for them to get scammed is still much lesser there.