Replying to Should i press charges?

On Wednesday night chilling in the park after school with some mates having a few drinks and we ran out at about 9 o'clock. Me and one other guy went to buy another slab and on the way back some Lads asked me for some darts as i was carrying the slab and only had rollies in my back pocket i told him i couldn't be fucked rolling him any, then he started asking for some beers and i told him to fuck off, after which he started getting really close and told me to give him the slab which i once again blatantly refused. One of them then hit me in the back of the head a couple of times and they asked for the slab again with yet another refusal, after that the bigger one (pics later) bottled me with his fucking beer in the side of my head and the other ripped the slab out of my hands.
They then ran off i started after them until one pulled a knife and called me out, i backed the fuck off (didn't feel like getting stabbed surprisingly) and my mate was already on the phone to the cops. they showed up and started looking for them but no luck.

The next day i asked some mates who i thought would know them and he gave me some names which i looked up on facebook and its definitely them. also asked what they were like and apparently they would have stabbed me without hesitation and they often hang around the exact same area as me and most of my friends so its likely i will run into them again.

So i ask you NS should i press charges on them? all i really wanted from the cops was to get our slab back and thats not going to happen anymore. If i do press charges and i run into them again which is quite likely then i'm likely to get stabbed. I have to see the cops tomorrow morning to give a visual description (they dont know i have their names) so should i just let it go or press charges?


SPARKNOTES: Got rolled for a slab of beer by some local lads and i found out their names but i am likely to run into them again so dont know if i should press charges.