Why is this happening to me?

So I'm a support main and the weirdest thing has happened to me twice this week. So I obviously got support on both these games and I lock in my support first before the adc and at last minute they troll and say "you're the adc" like wtf... I dont adc I suck at adc. I used to. Main it a loooong time ago but I'm just peer crap at it now. Idk I'm just ranting lol