So they're robbing merchants? Hahaa, you have a perfect reason to beat them to half-death (or completely to death, whatever rocks your boat) and then take them to guards to become criminal slaves! What are you waiting for?! Act now!
I've also never understood why MCs tend to stay silent and act all shocked that someone disagrees with them. Just tell them to "mind their own business and go die in a ditch on their own". Should either incite them into attacking you, or stop talking to you. Both count as a win in my book (since if they attack you, you can "deal" with them in "self defense", and if they stop talking to you, well, you don't have to listen to their self-righteous bs).