Off topic (black belt,my self) Belts dosent matter,but if you practise for competitions and do sparring with full contact that will give you enought to survive 2 randoms in street with out weapons if needet (running as fast as you can is best choise ofc).Years of sparring/competition gives you eye to read your oponent moves and with full contact training you get used to pain from opponents kicks/hits. On topic Sorry to hear this kind of thinks happening and you didnt do nothing wrong there.I just hope those guys pick "wrong" person next time they gonna jump on some one.