You can't be surprised there are scammers and imposters on Telegram. It's very easy to change your username into something that looks like something else. It's almost as if it's designed to facilitate scamming.
I wouldn't be surprised if the owner had that in mind and that regardless of all the constructive criticism, he still refuses to introduce some changes that would make it impossible for his app to be a paradise for scammers.
@God Of Thunder, considering the work you do, wouldn't it be logical to try to switch your communications to another app? I won't name any, but there are several that are far better and more private than Telegram.