Water Ingress due to lack of flashing

[vegmonkey]

Hi, we recently instructed a roofer to replace our concrete flashing on the roof of our 2 bed terraced victorian house. He turned up, spent a day remove the concrete flashing, then left. It has since rained, and after looking up in the loft, i've found

1.significant drips/dribbles from the roof onto boarded floor
2.damp roof beams in places
3.stained bricks on inside
4.water pooling on underside of roof covering

I'd like to know (after the lead flashing has been put in), what other work will need to be done to stop future problems i.e. damp, rotten joists etc.

Thanks in advance