...Was nobody thinking when they implemented this? I mean, seriously, they could've fixed that by having it so that if you confirmed by voice that you could hear and speak, then they'd cut you off.

I like what one US agency I called a while back did: they'd show a TTY message along the lines of "please stand by", then play a voice message telling hearing people that they've called the wrong number, then connect you to the TTY operator. That also makes perfect sense.