Sorry to hear the news, but right to report to the police and get an incident number.........as more and more insurance companies are offering repairs for hit and runs that do not affect your NCB - hopefully yours is one of those, so you might like to check it.
The fact you got the reg number is a bonus so chase up the police as to whether they have interviewed the registered owner as if they have evidence then irrespective of the 'hit & run' cover you should have a good case against the other party having failed to stop.