What would you do if you were in my situation?

The last Saturday I was waiting my friend out of his house when 5 persons in the same age with me came and hit me (some of them were hitting me, as the others were holding me down and I wasn't able to do anything...)... I wasn't ready for this, because they thought that I insulted them while I was sitting in the same bar with them and I didn't even know them... I'm doing martial arts for long time and the last 2 years I am training in kickboxing... I asked my master what to do with those guys and he told me that I did the best thing that I didn't continue this story.. What would you do?